CN209754880U - Grinding tool for self-sharpening grinding and polishing of fixed abrasive - Google Patents

Abstract

The utility model discloses a grinding tool for self-sharpening grinding and polishing of fixed abrasive, which comprises a connecting rod and a grinding chassis which are connected with each other, wherein the connecting rod is connected with a device for driving the connecting rod to rotate; the centers of the connecting rod, the grinding base plate and the grinding pad are all provided with pipelines for circulating grinding fluid; and the grinding liquid is rotationally sprayed out from a pipeline opening on the end surface of the grinding pad to the surface of the workpiece through the pipeline. The utility model discloses a lapping liquid is from the grinding tool center to supplying with all around, for supplying liquid all around, the abrasive particle supplies with more abundant, even in the whole processing region, increases the lubricated effect of the instrument of throwing of grinding, reduces the speed of peeling off of the surperficial abrasive particle of grinding pad, improves the grinding pad's of consolidation abrasive material self-sharpening nature simultaneously.

Description

Grinding tool for self-sharpening grinding and polishing of fixed abrasive

Technical Field

The utility model belongs to the optical machining field relates to the grinding means, in particular to consolidation abrasive material grinds the grinding means of throwing from sharp nature.

Background

At present, the traditional grinding is a contact type processing method using free abrasive materials, a soft grinding chassis is used as a polishing tool, and the rotation of the tool drives abrasive particles to wipe the surface of a workpiece to remove materials. In order to obtain higher surface quality and lower subsurface damage, softer abrasive particles, such as cerium oxide, silicon dioxide and the like, are generally used for processing the surface of a material, and due to the fact that the hardness of the abrasive is lower, the abrasive particles are free in a grinding fluid and cannot provide larger shearing force, and the material removal efficiency is lower. Meanwhile, the free abrasive grinding technique is a contact type processing method, and the stability of the removal efficiency is affected by various factors, such as abrasion of the grinding pad, insufficient supply of the grinding liquid, and the like. The traditional mode of supplying liquid adopts the nozzle to spout lapping liquid around the work piece, but when the grinding tool rotational speed constantly increases, because the effect of centrifugal force, lapping liquid hardly gets into the central zone of lapping pad or work piece, leads to central zone to supply liquid insufficient, and lubricated condition worsens, and lapping pad wearing and tearing speed is fast, and the grit gathers into a group, and the processing heat and get rid of the piece and can't in time discharge, lead to the surface quality to worsen. In summary, the free abrasive grinding method has limited removal efficiency and processing quality, and cannot meet the requirements of rapid development of semiconductor and optical industries on rapid processing of hard and brittle materials.

In recent years, chemical mechanical polishing technology has been developed, which improves the efficiency of material removal in polishing processing by changing the composition of a polishing liquid based on a free abrasive polishing processing method. By adding chemical reagents such as an oxidant and a complexing agent into the grinding fluid, the oxidizability of the grinding fluid is improved, the complexing reaction between abrasive particles in the grinding fluid and the surface of a workpiece is promoted, the chemical erosion of the abrasive particles to the workpiece is increased, a chemical reaction deterioration layer is formed, the deterioration layer is mostly in a loose and porous structure, and the mechanical property of the deterioration layer is far less than that of a workpiece base material, so that the abrasive particles can be removed easily, and the grinding removal efficiency is improved. However, the chemical mechanical polishing mainly depends on the action of chemical reagents, increases the pressure on the environment, has poor process stability, high cost and serious environmental pollution, runs counter to the clean and efficient processing concept, and can form a chemical reaction deterioration layer on the surface of a workpiece after processing to influence the service performance of the workpiece.

The fixed abrasive grinding technology is characterized in that abrasive grains are fixed in a base material of a grinding pad, and deionized water is used as grinding liquid, on one hand, the fixed abrasive grinding technology is a clean processing method, on the other hand, as the abrasive grains are embedded on the base material of the grinding pad, the shearing force provided by the abrasive grains is large, the removal efficiency is high, the abrasive grains cannot be agglomerated, and the obtained subsurface is less in damage. However, the fixed abrasive technology is still a contact processing method, the removal stability is greatly affected by the number and distribution of the abrasive particles on the surface of the polishing pad, the self-sharpening of the polishing pad is very important, and if the abrasive particles on the surface layer fall off, the base material cannot be removed, the abrasive particles on the next layer cannot be exposed in time, the surface material of the workpiece cannot be continuously removed, and the fixed abrasive pad cannot be continuously used. Therefore, the polishing pad needs to be continuously dressed for continuous use, which increases the processing period of the workpiece and the labor intensity of operators.

In summary, in order to solve the problems of the fixed abrasive polishing technique, such as poor self-sharpening, short service life, continuous dressing during the processing, and failure of the polishing solution to enter the processing center region due to the adoption of the mid-periphery solution supply mode during the high-speed processing, a new process measure is urgently needed to overcome the existing defects.

Disclosure of Invention

The utility model provides a consolidation abrasive material that improves self-sharpening and grinding tool life grinds the grinding tool of throwing from sharp nature for solving the technical problem that exists among the known art.

The utility model discloses a solve the technical scheme that technical problem that exists among the well-known technique took and be: a grinding tool for self-sharpening grinding and polishing fixed abrasive comprises a connecting rod and a grinding chassis which are connected with each other, wherein the connecting rod is connected with a device for driving the connecting rod to rotate; the centers of the connecting rod, the grinding base plate and the grinding pad are all provided with pipelines for circulating grinding fluid; and the grinding liquid is rotationally sprayed out from a pipeline opening on the end surface of the grinding pad to the surface of the workpiece through the pipeline.

further, the connecting rod and the grinding chassis are connected by a flexible coupling.

Further, a soft material interlayer is arranged between the grinding base plate and the grinding pad.

Further, the soft material interlayer is a sponge interlayer.

Further, the connecting rod is connected with an electric spindle provided with a central water outlet mechanism.

Furthermore, the front end of the connecting rod is provided with an ER chuck, and the ER chuck is connected with the electric spindle and locked.

The utility model has the advantages and positive effects that:

1. The center of the grinding tool is provided with a pipeline for circulating grinding fluid; the grinding fluid is sprayed to the surface of the workpiece from a pipeline port on the end face of the grinding pad in a rotating mode through the pipeline, and in the central fluid supply mode, the grinding fluid is supplied from the center of the grinding tool to the periphery. Therefore, the utility model discloses a material is got rid of efficiency is higher, is got rid of more stably.

2. The method for polishing the grinding pad by self-sharpening the solidified grinding material supplied by the center liquid adds the nano particles in the grinding liquid, and the nano particles are beneficial to removing the base material of the grinding pad in the grinding process, so that the next layer of abrasive particles is exposed in time, the self-sharpening performance of the grinding pad of the solidified grinding material is improved, the stability of the removal rate is maintained, the trimming times of the grinding pad in the processing process are reduced, the processing period of a workpiece is reduced, and the like.

3. Meanwhile, the existence of the nano particles can improve the lubricating property between the grinding tool and the processed surface, and the agglomeration phenomenon of the fixed abrasive can be effectively avoided due to the small size effect and the surface ratio effect of the nano particles, so that the distribution of the grinding particles on the processed surface is dispersed, the material removal rate of the processed surface is more uniform, and the destructive scratches are fewer.

Therefore, the nano particles are added into the consolidated abrasive grinding fluid, so that the self-sharpening performance of the grinding pad and the lubricating performance of the grinding and polishing tool and the surface of a workpiece are improved, and the dressing frequency of the grinding pad can be reduced. The grinding tool improves the supply mode of grinding liquid through central pipeline liquid supply, overcomes the problem of insufficient liquid supply in a central area, reduces the falling speed of abrasive particles on the surface of the grinding pad through improving the lubricating effect, stabilizes the removal efficiency, improves the controllability of the grinding and polishing process, and provides a new efficient and stable method for actual grinding and polishing processing.

Drawings

Fig. 1 is a schematic view of the structure of the grinding tool of the present invention.

Fig. 2 is a schematic diagram of the working principle of a prior art grinding tool.

FIG. 3 is a profile of a single point of plaque removal after a grinding experiment for a first set of experiments.

FIG. 4 is a profile of a second set of experiments with a single point of plaque removal after the grinding experiment.

FIG. 5 is a profile of a single point of plaque removal after the grinding experiment for the third set of experiments.

FIG. 6 is a graph comparing the maximum depth of removal for the first, second, and third sets of experimental results.

FIG. 7 is a photograph of a topography of an abrasive pad of a fixed abrasive prior to an experiment;

FIG. 8 is a photograph of the surface topography of the polishing pad after a first set of tests;

FIG. 9 is a photograph of the surface topography of the polishing pad after the third set of tests.

In the figure: 1. a connecting rod; 2. a liquid supply inlet; 3. an electric spindle; 4. a flexible coupling; 5. a hose; 6. grinding the base plate; 7. a soft material interlayer; 8. a polishing pad; 9. a workpiece; 10. grinding fluid; 11. a work table; 12. and (4) a nozzle.

Detailed Description

For further understanding of the contents, features and effects of the present invention, the following embodiments are listed and will be described in detail with reference to the accompanying drawings:

Referring to fig. 1, a fixed abrasive self-sharpening polishing and grinding tool includes a connecting rod 1 and a grinding chassis 6 connected to each other, the connecting rod 1 is connected to a device for driving the connecting rod to rotate, a grinding pad 8 is mounted on the grinding chassis 6, the grinding pad 8 is made of fixed abrasive, and the grinding pad 8 rotates with the grinding chassis 6 to grind the surface of a workpiece 9; the centers of the connecting rod 1, the grinding base plate 6 and the grinding pad 8 are all provided with pipelines for circulating grinding fluid 10; the polishing liquid 10 is rotationally ejected from a port of the pipe on the end surface of the polishing pad 8 toward the surface of the workpiece 9 through the pipe. As shown in fig. 1, the polishing liquid 10 is fed through the liquid feed inlet 2, along the pipe, and finally is ejected from the mouth of the pipe on the end face of the polishing pad 8 toward the surface of the workpiece 9.

Further, the connecting rod 1 and the grinding pan 6 may be connected by a flexible coupling 4. The connecting rod 1, grind chassis 6 and 8 three centers of grinding pad can be opened there is the hole that link up, downthehole pipeline that is equipped with circulation lapping liquid 10, because connecting rod 1 and grinding chassis 6 are hollow structure, can embedded hose 5 in the pipeline that both link to each other, because connecting rod 1 and grinding chassis 6 are hollow structure, and lapping liquid 10 accessible hose 5 circulates. The sealing requirements at both ends of the hose 5 will increase with increasing supply pressure. Secondly, in order to compensate clamping errors, improve the vibration resistance of the tool, and improve the adhesion between the tool and the workpiece 9 and the uniformity of contact pressure, the connecting rod 1 and the grinding base plate 6 can be connected by using a flexible coupling 4.

further, a soft material interlayer 7 may be provided between the polishing base plate 6 and the polishing pad 8. The soft material interlayer 7 can be a sponge interlayer. To further improve the conformity of the tool to the surface of the workpiece 9, a soft sponge interlayer is added between the abrasive chassis 6 and the abrasive pad 8.

further, the connecting rod 1 can be connected with an electric spindle 3 provided with a central water outlet mechanism. The connecting rod 1 is driven by the electric spindle 3 to rotate, so that the grinding chassis 6 and the grinding pad 8 mounted on the grinding chassis are driven to rotate. The grinding fluid 10 circulation pipeline at the center of the connecting rod is communicated with the fluid channel of the central water outlet mechanism of the electric spindle 3.

Further, in order to ensure the positioning and sealing functions of the device, the front end of the connecting rod 1 can be provided with an ER chuck, and the ER chuck can be connected and locked with the electric spindle 3. The connecting rod 1 can be connected with the electric spindle 3 by adopting an ER chuck and locked by an ER nut, thereby achieving the purposes of positioning and sealing.

The utility model also provides an embodiment of the grinding method that the abrasive material that solidifies is from sharp grinding and polishing, this method adopts and installs grinding pad 8 on the grinding tool, grinding pad 8 is made by the abrasive material that solidifies, grinding pad 8 rotates along with the grinding tool and grinds 9 surfaces of work pieces, uses lapping liquid 10 to spray the processing area when grinding work pieces 9, the grinding tool center is equipped with the pipeline that is used for circulating lapping liquid 10; the polishing liquid 10 is rotationally ejected from a port of the pipe on the end surface of the polishing pad 8 toward the surface of the workpiece 9 through the pipe.

Furthermore, nanoparticles can be added into the grinding fluid 10, and the concentration of the nanoparticles in the grinding fluid 10 can be 0.01-15%. Further, the nanoparticles of the polishing slurry 10 may be one or a combination of cerium oxide nanoparticles, aluminum oxide nanoparticles, and silicon dioxide nanoparticles. The combination ratio can be arbitrary. The self-sharpening polishing method of the fixed abrasive by central liquid supply adds the nano particles in the grinding liquid 10, and the nano particles are beneficial to removing the base material of the grinding pad 8 in the grinding process, so that the next layer of abrasive particles is exposed in time, the self-sharpening performance of the grinding pad 8 of the fixed abrasive is improved, the stability of the removal rate is maintained, the trimming times of the grinding pad 8 in the processing process are reduced, the processing period of the workpiece 9 is shortened, and the like.

Further, the pressure of the polishing slurry 10 in the pipeline may be 0.1 to 1.0 MPa.

the utility model discloses a theory of operation:

The utility model discloses in, use deionized water as lapping liquid 10 for traditional consolidation abrasive grinding, the utility model discloses improve lapping liquid 10, added the nanometer abrasive particles such as cerium oxide or silica of certain concentration in lapping liquid 10, increase consolidation abrasive's grinding pad 8's sharp nature certainly, after making the top layer abrasive particle take off, base material can obtain continuous erosion and wear, and then makes the one deck abrasive particle in time expose down, keeps getting rid of efficiency stability, reduces grinding pad 8's the number of times of repairing.

The traditional fixed abrasive grinding adopts deionized water as grinding fluid 10, and although the grinding fluid is cleaner and can take away processed scraps and processing heat, the grinding fluid does not directly improve the removal efficiency and maintain the stability of the removal efficiency. In the grinding process, the roughness of the processed plane is often micron or submicron, the surface quality is high, when the abrasive grains on the surface layer of the grinding pad 8 for solidifying the abrasive are removed by long-time cutting, the abrasive grains are loosened and fall off from the surface of the base material of the grinding pad 8, at the moment, the base material of the grinding pad 8 is directly contacted with the surface of the workpiece 9, however, the surface of the grinding workpiece 9 is flat and has high surface quality, even if the hardness of the workpiece 9 is very large, the base material of the grinding pad 8 cannot be trimmed, the base material is timely peeled off, and only a few abrasive grains on the surface layer are exposed after grinding for a certain time, and the surface material can hardly be continuously removed. And by adding a certain concentration of abrasive particles into the polishing solution 10, in the polishing process, the abrasive particles are directly contacted with the base material of the polishing pad 8 after being extruded between the base material of the polishing pad 8 and the workpiece 9, generally, the base material of the polishing pad 8 is a resin bond or a metal bond, the hardness or the abrasion resistance is smaller than that of the abrasive particles and the workpiece 9, and the abrasive particles are easily abraded, crushed and peeled off under the action of the abrasive particles, so that the abrasive particles can be exposed out of the surface in time, and the surface of the workpiece 9 is continuously processed and removed.

The method of the present invention improves the supply method of the grinding fluid 10 on the basis of the conventional fixed abrasive grinding, and as shown in fig. 1, the grinding fluid 10 is supplied from the center to the periphery.

The utility model discloses in, be different from traditional grinding technology lapping liquid 10 feed mode, the utility model discloses an innovation part lies in the transformation of liquid feed mode, supplies with lapping liquid 10 from the instrument center, very big improvement lapping liquid 10's distribution and utilization efficiency. The present invention is directed to a grinding tool, in which a grinding liquid 10 can be supplied from a central region of the tool with a constant pressure and smoothly and stably during normal operation.

In a conventional polishing process, a workpiece 9 is placed on a table 11, and deionized water is sprayed around the rotating workpiece 9 through a nozzle 12 as shown in fig. 2. The utility model discloses a center go out the grinding tool of water, as shown in figure 1, choose for use the electricity main shaft 3 that has the center function of going out water to carry on the center and supply liquid grinding tool. Experiments show that the structure can meet the sealing requirement when the liquid supply pressure is less than or equal to 1.0 Mpa. In the experiment, the small flow supply of the grinding liquid 10 can be kept, and the material removal mechanism is basically the same as that of the traditional fixed abrasive grinding.

The utility model discloses a grind the clearance and get rid of stability contrast experiment:

The grinding fluid 10 is supplied from the center of the tool, the liquid supply mode is called center liquid supply for short, and the traditional grinding mode of the fixed abrasive adopts deionized water which is sprayed to the periphery of the rotating workpiece 9 through a nozzle 12, and the liquid supply mode is called periphery liquid supply for short. And analyzing the processing effect conditions generated by two different liquid supply modes, different grinding liquids 10 and grinding methods, and carrying out fixed-point grinding processing experiments.

The experiment was divided into three groups:

In the first group, a fixed abrasive polishing pad 8 (diamond abrasive grains with a particle size of 10 μm) and deionized water are used as a polishing solution 10, the solution is supplied in a manner of supplying liquid all around at a rotation speed of 800rpm, three points are sequentially polished, each point stays for 30s, and the polishing pad 8 is not trimmed.

And in the second group, a grinding pad 8 (diamond abrasive grains with the grain diameter of 10 microns) of fixed abrasive is adopted, nano cerium oxide grinding fluid 10 (abrasive grains with the grain diameter of 30nm and the concentration of 12%) is adopted, liquid is supplied all around in a liquid supply mode, the rotating speed is 800rpm, three points are sequentially ground, each point stays for 30s, and the grinding pad 8 is not trimmed in the period.

And in the third group, a grinding pad 8 (diamond abrasive grains with the grain diameter of 10 microns) of fixed abrasive is adopted, nano cerium oxide removing grinding liquid 10 (abrasive grains with the grain diameter of 30nm and the concentration of 12%) is adopted, liquid is supplied by a liquid supply mode, the rotating speed is 800rpm, three points are sequentially ground, each point stays for 30s, and the grinding pad 8 is not trimmed in the period.

The experimental results are shown in fig. 3 to 9, wherein fig. 3 to 5 show the outline of a single-point spot removal after the grinding experiment of each group of experimental points, fig. 6 shows the comparison of the maximum removal depths of each group of experimental results, fig. 7 shows the morphology of the polishing pad 8 of the fixed abrasive before the experiment, fig. 8 shows the surface morphology of the first group of polishing pad 8 after three points are ground, and fig. 9 shows the surface morphology of the third group of polishing pad 8 after three points are ground.

Observing the removal profiles and the maximum removal depths of the groups of removal profiles in fig. 3 to 5, on one hand, the maximum removal depths are sequentially reduced along with the sequence of the processing points, which shows that in the three grinding methods, the grinding pad 8 for solidifying the grinding materials is worn to a certain extent, and the surface abrasive grains of the grinding pad 8 are peeled off, so that the removal rate is reduced, but observing the change situation of the removal depths of the groups shows that when the grinding liquid 10 is supplied with the abrasive grains at the periphery, the change probability of the maximum removal depth is substantially consistent with that when deionized water is used, however, when the central liquid supply is used and the abrasive grains are added to the grinding liquid 10, the change trend of the maximum removal depth is obviously improved, and the maximum removal depth of the third point is very close to the second point, which shows that the abrasive grains can be more uniformly distributed between the grinding pad 8 and the workpiece 9 by the central liquid supply, so that the base material on the surface of, the abrasive particles are updated in time, the removal efficiency is kept stable, and the dressing frequency of the grinding pad 8 for solidifying the abrasive is reduced. On the other hand, as a result of observing the comparison of the maximum removal depths of the experimental results in fig. 6, it is found that, in the four-side liquid supply manner, after cerium oxide abrasive grains with a certain concentration are added to the polishing liquid 10, the maximum removal depths are greater than those of the polishing method using deionized water, because the polishing time is very short, the soft abrasive grains are not removed from the surface of the workpiece 9, which indicates that the abrasive grains of the polishing pad 8 can be updated in time by adding the cerium oxide abrasive grains, and the removal efficiency of polishing is improved. After the grinding liquid 10 added with the abrasive particles is adopted, the removal efficiency is further improved by adopting a central liquid supply mode, and the stability of the removal rate is improved, which shows that the grinding liquid 10 is sufficiently supplied by adopting the central liquid supply mode, the problem that the grinding liquid 10 is difficult to enter a processing area during high-speed grinding in a traditional peripheral liquid supply mode is solved, and the self-sharpening performance of the grinding pad 8 for solidifying the grinding materials in the processing process is improved.

Meanwhile, the result of observing fig. 3 shows that when a grinding mode of supplying liquid around without adding abrasive grains is adopted, the shape of the removal profile changes greatly along with the sequence of the processing points, and the profile of the third point shows that when the grinding pad 8 is used for 60s-90s, the central area of the single-point removal spot profile is not removed basically, which indicates that a large amount of abrasive grains on the surface fall off, and meanwhile, the abrasive grains in the central area fall off faster than around because the grinding liquid 10 cannot enter the central area. On the other hand, the observation of fig. 4 and 5 shows that the removal profile has higher consistency, which indicates that the addition of the abrasive grains greatly plays a role in renewing the abrasive grains of the fixed abrasive polishing pad 8, and increases the self-sharpening performance of the fixed abrasive polishing pad 8.

observing the initial appearance of the grinding pad 8 in fig. 7, the observation result of a scanning electron microscope shows that the initial surface abrasive particle density is high, the abrasive particle exposure condition is good, and observing the result in fig. 8 shows that after the grinding mode of supplying liquid around without abrasive particles is adopted for grinding, no obvious abrasive particles can be seen on the surface of the grinding pad 8, which indicates that after the surface abrasive particles fall off, the base material of the grinding pad 8 cannot be worn and fall off due to high surface quality, and the next layer of abrasive particles cannot be exposed in time. As a result of observing fig. 9, it was found that, after polishing with a polishing method in which nano-abrasive grains were added to the center liquid supply, a significant new exposed abrasive grain surface was observed on the surface of the polishing pad 8 in which abrasive grains were fixed. The method of central liquid supply and adding the nano abrasive particles into the grinding liquid 10 is beneficial to improving the self-sharpening performance of the grinding pad 8 of the fixed grinding material.

To sum up, the utility model provides a center supplies liquid consolidation abrasive material from sharp nature grinding method can make lapping liquid 10 supply with more sufficient, improves the self-sharpening nature that consolidation abrasive material ground, improves the material of grinding technology and gets rid of efficiency, improves the stability of getting rid of the profile, is favorable to improving machining efficiency, shortens processing cycle.

The above-mentioned embodiments are only used for illustrating the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and to implement the present invention accordingly, the scope of the present invention should not be limited by the embodiment, that is, all equivalent changes or modifications made by the spirit of the present invention should still fall within the scope of the present invention.

Claims (6)

1. A grinding tool for self-sharpening grinding and polishing fixed abrasive comprises a connecting rod and a grinding chassis which are connected with each other, wherein the connecting rod is connected with a device for driving the connecting rod to rotate; the polishing machine is characterized in that the centers of the connecting rod, the polishing base plate and the polishing pad are all provided with pipelines for circulating polishing liquid; and the grinding liquid is rotationally sprayed out from a pipeline opening on the end surface of the grinding pad to the surface of the workpiece through the pipeline.

2. The fixed abrasive self-sharpening abrasive tool of claim 1, wherein said connecting rod and said abrasive chassis are connected by a flexible coupling.

3. The fixed abrasive self-sharpening polishing tool as recited in claim 1, wherein a soft material interlayer is provided between said polishing base plate and said polishing pad.

4. The fixed abrasive self-sharpening abrasive tool of claim 3, wherein the soft material interlayer is a sponge interlayer.

5. The fixed abrasive self-sharpening abrasive tool of claim 1, wherein the connecting rod is connected to an electric spindle provided with a central water outlet mechanism.

6. The fixed abrasive self-sharpening abrasive tool according to claim 5, wherein said connecting rod is provided at a front end thereof with an ER collet, and said ER collet is coupled and locked to said electric spindle.