Atmospheric plasma assisted workpiece self-rotation grinding device and method

Abstract

The invention discloses an atmospheric plasma assisted workpiece self-rotation grinding device and method, comprising a base and workpiece power structure, a grinding device power structure, an atmospheric plasma activation and power structure, and a grinding device displacement mechanism; the base and workpiece power structure refers to the workpiece rotation axis under the action of a fourth servo motor to realize the self-rotation of the workpiece; the grinding device power structure refers to the grinding spindle under the action of a third servo motor to realize the self-rotation of a grinding wheel; the atmospheric plasma activation and power structure is jointly realized by an atmospheric plasma spray gun power structure and an atmospheric plasma activation system; the atmospheric plasma spray gun power structure refers to the atmospheric plasma spray gun realizing self-rotation under the action of a first servo motor; the atmospheric plasma activation system refers to the oxidation gas being activated by a radio frequency power supply coil under the protection of an inert gas, and sprayed onto the workpiece to oxidize it into a loose soft modified layer, thereby effectively improving the grinding efficiency and quality.

Description

Technical Field

[0001] The invention relates to the technical field of grinding, and in particular to an atmospheric plasma assisted workpiece self-rotation grinding device and method. Background Art

[0002] The processing accuracy, surface roughness and surface integrity of the wafer substrate directly affect the characteristic line width and performance of the chip, so it is crucial to achieve high-efficiency, high-quality flattening processing of the wafer substrate. However, the wafer substrate is a hard and brittle material with weak chemical reaction. It is often affected by factors such as tool performance, machine tool accuracy, and material properties during processing using traditional processing methods. It is difficult to achieve high-efficiency and ultra-smooth manufacturing, and cracks and scratches often appear on its surface, causing sub-surface damage. For example, patent CN202021897451.7 proposes a wafer grinding mechanism, which adopts a new type of grinding plate. The grinding sheet is tilted relative to the grinding table. When working, there is point contact between the grinding sheet and the wafer, which can improve the stability of grinding, ensure the quality of grinding, and avoid the problem of burning or broken pieces on the outer surface of the wafer. However, the point contact grinding process is inefficient, and the temperature at the grinding position is too high, which has a certain impact on the accuracy. Patent CN202022947188.4 mentions a double-sided thinning processing device for a 4-inch LED sapphire substrate, which can grind both sides of the sapphire substrate to improve processing efficiency. However, the high hardness of the sapphire substrate still greatly affects the processing efficiency, and the long-term grinding also greatly increases the cost. For this reason, plasma-assisted wafer machining is introduced to effectively improve the processing accuracy and efficiency of the wafer. Atmospheric plasma-assisted grinding can oxidize the workpiece surface into a loose and soft modified layer, effectively improving the grinding efficiency and quality to achieve processing.

[0003] Therefore, how to provide a new grinding device and grinding method to improve the processing quality and processing efficiency of the workpiece surface is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problems existing in the prior art and to provide an atmospheric plasma assisted workpiece self-rotation grinding device and method.

[0005] To achieve the above-mentioned purpose, the technical solution provided by the present invention is: an atmospheric plasma assisted workpiece self-rotation grinding device, comprising a base and workpiece power structure, a grinding device power structure, an atmospheric plasma activation and power structure and a grinding device displacement mechanism;

[0006] The base and workpiece power structure includes a base plate, a convex base plate, an arched bracket, a third pulley rotating shaft, and a workpiece shaft rotating shaft. The convex base plate is fixed to the upper end of the base plate by a ninth fastening screw; the arched bracket is fixed to one side of the base plate; a fourth servo motor is fixed to the convex base plate; the rotating shaft of the fourth servo motor is connected to the rotating shaft of the third pulley by a third coupling; a third driving pulley is fixed to the rotating shaft of the third pulley by a third fastening nut; a third driven pulley is fixed to the rotating shaft of the workpiece by a fourth fastening nut; the third driving pulley and the third driven pulley are driven by a third synchronous belt; a porous ceramic suction cup is fixed to the upper end of the workpiece rotating shaft; the workpiece rotating shaft is installed inside the convex base plate by a fifth tapered roller bearing and a sixth tapered roller bearing;

[0007] The displacement mechanism of the grinding device includes a moving slider, a screw, a second servo motor, and a rotating shaft of the second servo motor. The moving slider is displaced up and down by the screw. The second servo motor is installed on the upper end of the arch bracket; the screw is connected to the rotating shaft of the second servo motor through a fourth coupling; the screw is positioned by a bearing base; the bearing base is fixed to the arch bracket by an eleventh fastening screw;

[0008] The power structure of the grinding device includes a grinding spindle, a grinding wheel fastener, a third servo motor, and a second pulley rotating shaft. A grinding wheel is installed on the grinding wheel fastener, and the grinding wheel fastener is installed at the lower end of the grinding spindle. The grinding spindle is installed inside the moving slider through a first tapered roller bearing and a second tapered roller bearing; the third servo motor is fixed on the moving slider; a second driven pulley is fixed on the grinding spindle through a shoulder of the grinding spindle and a second shaft sleeve; a second driving pulley is fixed on the second pulley rotating shaft through a second fastening nut; the second pulley rotating shaft is connected to the third servo motor rotating shaft through a second coupling; the second driving pulley and the second driven pulley are driven by a second synchronous belt;

[0009] The atmospheric plasma activation and power structure comprises a plasma spray gun, an inner sleeve of a gas rotary joint, an outer sleeve of a gas rotary joint, a first servo motor and a first pulley rotating shaft. The plasma spray gun is installed inside a movable slider through a third tapered roller and a fourth tapered roller; a radio frequency power supply coil is arranged between the plasma spray gun and the grinding spindle; the inner sleeve of the gas rotary joint is fixed to the upper end of the plasma spray gun; the outer sleeve of the gas rotary joint is fixed to the movable slider through a fourth fastening screw; the inner sleeve of the gas rotary joint and the outer sleeve of the gas rotary joint are connected through a first deep groove ball bearing and a second deep groove ball bearing; the first servo motor is installed on the movable slider; the first pulley rotating shaft is connected to the first servo motor rotating shaft through a first coupling; a first driving pulley is fixed to the first pulley rotating shaft through a first fastening nut; the first driving pulley is driven by a first synchronous belt and a first driven pulley; the first driven pulley is positioned through a third shaft sleeve and a plasma spray gun shoulder.

[0010] Preferably, the porous ceramic suction cup in the base and the workpiece power structure adsorbs a 2-12 inch workpiece; the fourth servo motor drives and controls the workpiece rotating shaft to adsorb the workpiece and rotate at a speed of 10-150 r / min; the fifth tapered roller bearing and the sixth tapered roller bearing are positioned through the shoulder of the workpiece rotating shaft, the sixth shaft sleeve, the eighth flange and the ninth flange; the eighth flange and the ninth flange are respectively installed on the convex bottom plate through the eighth fastening screw and the tenth fastening screw.

[0011] Preferably, the second servo motor in the displacement mechanism of the grinding device drives the lead screw to control the up and down displacement of the grinding spindle, thereby achieving an axial feed speed of the grinding spindle of 0.1 to 10 μm / s.

[0012] Preferably, the third servo motor in the power structure of the grinding device drives and controls the grinding wheel fastener installed on the grinding spindle to clamp the grinding wheel and rotate at a speed of 1000~3000 r / min. The grinding wheel is in the shape of an annular sheet, a circular sheet, a square sheet or a polygonal sheet, and the sheet-shaped grinding wheel is arranged in one or more circles in an annular shape; the first tapered roller bearing and the second tapered roller bearing are positioned by the first flange, the second flange, the first shaft sleeve and the second shaft sleeve; the first flange and the second flange are fixed to the movable slider by the first and second fastening screws and the second fastening screws respectively.

[0013] Preferably, the first servo motor in the atmospheric plasma activation and power structure drives the plasma spray gun to rotate at a speed of 10 to 100 r / min, and the plasma spray gun has a single hole or a multi-hole structure, and the shape of the hole is circular, square or polygonal; the RF power supply coil activates the oxidizing gas into plasma through an external RF power supply, wherein the number of coil turns, coil thickness, and RF power supply power are all adjustable.

[0014] Preferably, the outer sleeve of the gas rotary joint and the inner sleeve of the gas rotary joint are provided with a hole or multiple holes for gas flow channels, the oxidizing gas is transported to the excitation area of ​​the RF power supply coil through the central pipe, and an inert gas annular groove and an oxidizing gas annular groove are provided between the outer sleeve of the gas rotary joint and the inner sleeve of the gas rotary joint, so that the stability of gas inflow is always maintained during the rotation of the inner sleeve of the gas rotary joint; the type, ratio, flow rate, flow velocity and pressure of the oxidizing gas and the inert gas are adjusted according to demand.

[0015] Preferably, the third tapered roller bearing and the fourth tapered roller bearing in the atmospheric plasma activation and power structure are positioned by a third flange, a fourth flange, a third shaft sleeve, and an inner sleeve of a gas rotary joint; the third flange and the fourth flange are fixed by a third fastening screw and a fourth fastening screw, respectively; the first deep groove ball bearing is positioned by a fifth flange, a sixth flange, a second shaft sleeve, and a third shaft sleeve; the second deep groove ball bearing is positioned by a sixth flange, a seventh flange, a fourth shaft sleeve, and a fifth shaft sleeve; the sixth flange is fixed to the inner sleeve of the gas rotary joint by a sixth fastening screw; the fifth flange and the seventh flange are fixed to the outer sleeve of the gas rotary joint by a fifth fastening screw and a seventh fastening screw, respectively.

[0016] Preferably, the inner sleeve and the outer sleeve of the gas rotary joint are provided with an oxidizing gas inlet and an inert gas inlet, and the oxidizing gas inlet is also provided with a first sealing ring, a second sealing ring and a third sealing ring to prevent gas leakage.

[0017] The present invention also discloses an atmospheric plasma assisted workpiece self-rotation grinding method, comprising any one of the atmospheric plasma assisted workpiece self-rotation grinding devices described above, the method comprising the following steps:

[0018] 1) According to the structure of the machine tool, an atmospheric plasma-assisted workpiece self-rotation grinding device is designed and adapted;

[0019] 2) Select a suitable grinding wheel and connect it to the grinding wheel fastener through screws, place the grinding wheel dresser on the porous ceramic suction cup, and start the porous ceramic suction cup; use the tool setting block to set the tool, set the workpiece coordinates, grinding wheel dressing amount and z-direction feed speed;

[0020] 3) Start the fourth servo motor to drive the workpiece to rotate at a speed of 10-150 r / min, start the third servo motor to drive the grinding wheel to rotate at a speed of 10-100 r / min, start the second servo motor to make the grinding spindle axially feed at a speed of 0.1 μm / s-10 μm / s, and realize the grinding wheel dresser to correct the grinding wheel by 10-50 μm removal;

[0021] 4) After the grinding wheel is corrected, use an oil stone to clean the surface of the workpiece table; adsorb the workpiece on the porous ceramic suction cup, and make the workpiece located within the grinding range of the grinding device, use the tool setting block to set the tool, set the working coordinate system, machining allowance and z-direction feed speed;

[0022] 5) According to the characteristics of the processing object, select appropriate oxidizing gas and inert gas, and use a suitable RF power coil to install it inside the grinding spindle;

[0023] 6) Start the gas pump, control the gas velocity, flow rate and pressure, and inject oxidizing gas and inert gas into the plasma spray gun at a certain rate;

[0024] 7) Starting the external RF power supply of the coil, the RF power supply coil is energized to activate the oxidizing gas in the plasma spray gun 6 to form plasma;

[0025] 8) Start the fourth servo motor to drive the workpiece rotating shaft to rotate, so that the workpiece rotating shaft drives the workpiece to rotate at a speed of 50~500r / min; start the third servo motor to drive the grinding spindle to rotate, so that the grinding wheel clamped on the grinding spindle rotates at a speed of 10~100 r / min; start the first servo motor to drive the plasma spray gun to rotate, so that the plasma spray gun rotates at a speed of 10~100 r / min;

[0026] 9) Start the second servo motor to lower the grinding wheel to a height of 1-5 mm from the workpiece, reduce the speed of the second servo motor, and make the grinding wheel grind the workpiece surface at an axial feed speed of 0.1-10 μm / s; after the hard and brittle materials are modified by plasma oxidation, oxides that are easier to remove are formed on the workpiece surface, and the abrasive group particles can grind the oxides on the workpiece surface efficiently, ultra-smoothly and without damage through the relative motion between the workpiece and the grinding wheel.

[0027] Beneficial effects of the present invention:

[0028] In the present invention, the oxidizing gas and the inert gas flow in from the oxidizing gas inlet and the inert gas inlet respectively through the air pump. Since the outer sleeve of the gas rotary joint is provided with annular grooves at the oxidizing gas inlet and the inert gas inlet, the gas is stably injected into the plasma spray gun during the rotation of the plasma spray gun. When the oxidizing gas and the inert gas flow through the plasma activation area, the oxidizing gas is activated under the protection of the inert gas, and is uniformly sprayed on the workpiece under the action of the self-rotation of the plasma spray gun and the self-rotation of the workpiece rotating shaft, so that the surface of the workpiece is uniformly oxidized to form a loose soft modified layer, and the grinding efficiency and quality are effectively improved; the self-rotation of the grinding spindle drives the grinding wheel fastener to clamp the grinding wheel and the workpiece to rotate relative to each other, and the workpiece adsorbed on the workpiece rotating shaft by the porous ceramic suction cup is first uniformly oxidized by the plasma, and then is efficiently removed under the action of relative rotation, so that the surface quality is relatively high. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0030] Figure 1 A schematic diagram of the structure processing of an atmospheric plasma-assisted workpiece self-rotation grinding device;

[0031] Figure 2 It is a schematic diagram of the structure of an atmospheric plasma assisted workpiece self-rotation grinding device from the left;

[0032] Figure 3 A schematic top view of the structure of an atmospheric plasma assisted workpiece self-rotation grinding device;

[0033] Figure 4 It is a top view of the structure AA of an atmospheric plasma assisted workpiece self-rotation grinding device;

[0034] Figure 5 It is a top view of the structure BB of an atmospheric plasma assisted workpiece self-rotation grinding device;

[0035] Figure 6 This is a partial schematic diagram of the gas rotary joint of an atmospheric plasma-assisted workpiece self-rotation grinding device.

[0036] Figure annotation:

[0037] 1-base plate, 2-convex base plate, 3-screw, 4-grinding wheel, 5-grinding wheel fastener, 6-plasma spray gun, 7-RF power supply coil, 8-grinding spindle, 9-first shaft sleeve, 10-first fastening screw, 11-first flange, 12-first tapered roller bearing, 13-moving slider, 14-second tapered roller bearing, 15-second shaft sleeve, 16-first servo motor, 17-first servo motor rotating shaft, 18-second fastening screw, 19-second flange, 20-first coupling, 21-first pulley rotating shaft, 22-first driving pulley, 23-first synchronous belt, 24-first slave Driven pulley, 25-first fastening nut, 26-third fastening screw, 27-third flange, 28-third shaft sleeve, 29-third tapered roller bearing, 30-fourth tapered roller bearing, 31-fourth flange, 32-fourth fastening screw, 33-gas rotary joint outer sleeve, 34-gas rotary joint inner sleeve, 35-fifth flange, 36-fifth fastening screw, 37-first deep groove ball bearing, 38-second shaft sleeve, 39-third shaft sleeve, 40-bow bracket, 41-second servo motor, 42-sixth flange, 43-sixth fastening screw, 44-seventh fastening screw, 45-seventh Flange, 46-second deep groove ball bearing, 47-fourth shaft sleeve, 48-fifth shaft sleeve, 49-first sealing ring, 50-oxidizing gas inlet, 51-second sealing ring, 52-inert gas inlet, 53-third sealing ring, 54-second driven pulley, 55-second fastening nut, 56-second synchronous belt, 57-second driving pulley, 58-second pulley rotating shaft, 59-second coupling, 60-third servo motor rotating shaft, 61-third servo motor, 62-porous ceramic suction cup, 63-workpiece rotating shaft, 64-eighth fastening screw, 65-eighth flange, 66-fifth tapered roller Bearing, 67-sixth tapered roller bearing, 68-fourth servo motor, 69-fourth servo motor rotating shaft, 70-third coupling, 71-third pulley rotating shaft, 72-third driving pulley, 73-third fastening nut, 74-ninth fastening screw, 75-third synchronous belt, 76-tenth fastening screw, 77-sixth shaft sleeve, 78-third driven pulley, 79-fourth fastening nut, 80-ninth flange, 81-bearing base, 82-eleventh fastening screw, 83-fourth coupling, 84-second servo motor rotating shaft, 85-inert gas annular groove, 86-oxidizing gas annular groove. DETAILED DESCRIPTION

[0038] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0039] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0040] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0041] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0042] Reference Figure 1-Figure 6 The present invention provides an atmospheric plasma assisted workpiece self-rotation grinding device and processing method, which effectively improves the grinding efficiency and quality. The device includes: a base and workpiece power structure, a grinding device power structure, an atmospheric plasma activation and power structure, and a grinding device displacement mechanism. The present invention is suitable for the flattening and ultra-smooth surface grinding of optical elements, electronic and microelectronic substrates.

[0043] The base and workpiece power structure are arranged at the upper end of the bottom plate 1, the grinding device power structure and the atmospheric plasma activation and power structure are arranged at the upper end of the moving slider 13, and the atmospheric plasma activation and power structure is arranged inside the grinding device power structure; the grinding device displacement mechanism is installed on the arch bracket 40;

[0044] The base workpiece power structure includes a base plate 1, a convex base plate 2, a ninth fastening screw 74, an arch bracket 40, a fourth servo motor 68, a third coupling 70, a third pulley rotating shaft 71, a third driving pulley 72, a third fastening nut 73, a third driven pulley 78, a third synchronous belt 75, a fourth fastening nut 79, a workpiece rotating shaft 63, a porous ceramic suction cup 62, a fifth tapered roller bearing 66, a sixth tapered roller bearing 67, a sixth shaft sleeve 77, an eighth flange 65, a ninth flange 80, an eighth fastening screw 64, and a tenth fastening screw 76; the convex base plate 2 is fixed to the upper end of the base plate 1 by the ninth fastening screw 74; the arch bracket 40 is fixed to one side of the base plate 1; the fourth servo motor 68 is fixed on the convex base plate 2; the fourth servo motor rotating shaft 69 is connected to the third pulley by the third coupling 70 The third driving pulley 72 is connected to the third pulley rotating shaft 71 by a third fastening nut 73; the third driving pulley 72 and the third driven pulley 78 are driven by a third synchronous belt 75; the third driven pulley 78 is fixed to the workpiece rotating shaft 63 by a fourth fastening nut 79; a porous ceramic suction cup 62 is fixed to the upper end of the workpiece rotating shaft 63; the workpiece rotating shaft 63 is installed inside the convex base plate 2 by a fifth tapered roller bearing 66 and a sixth tapered roller bearing 67; the fifth tapered roller bearing 66 and the sixth tapered roller bearing 67 are positioned by the shaft shoulder of the workpiece rotating shaft 63, the sixth shaft sleeve 77, the eighth flange 65 and the ninth flange 80; the eighth flange 65 and the ninth flange 80 are respectively installed on the convex base plate 2 by the eighth fastening screw 64 and the tenth fastening screw 76.

[0045] The displacement mechanism of the grinding device includes a second servo motor 41, a second servo motor rotating shaft 84, a fourth coupling 83, a screw 3, a bearing base 81, an eleventh fastening screw 82, and a moving slider 13; the second servo motor 41 is installed on the upper end of the bow-shaped bracket 40; the screw 3 is connected to the second servo motor rotating shaft 84 through the fourth coupling 83; the screw 3 is positioned through the bearing base 81; the bearing base 81 is fixed to the bow-shaped bracket 40 through the eleventh fastening screw 82; the moving slider 13 is displaced up and down through the screw 3.

[0046] The power structure of the grinding device includes a third servo motor 61, a third servo motor rotating shaft 60, a second coupling 59, a second pulley rotating shaft 58, a second driving pulley 57, a second fastening nut 55, a second driven pulley 54, a second synchronous belt 56, a grinding spindle 8, a first tapered roller bearing 12, a second tapered roller bearing 14, a first flange 11, a second flange 19, a first shaft sleeve 9, a second shaft sleeve 15, a first fastening screw 10, a second fastening screw 18, a grinding wheel fastener 5, and a grinding wheel 4; the third servo motor 61 is fixed on the moving slider 13; the second pulley rotating shaft 58 is connected to the third servo motor rotating shaft 60 through the second coupling 59; the second driving pulley 57 is fixed to the second tapered roller bearing 12 through the second fastening nut 55. On the pulley rotating shaft 58; the second driving pulley 57 and the second driven pulley 54 are driven by the second synchronous belt 56; the second driven pulley 54 is fixed to the grinding spindle 8 through the grinding spindle 8 shoulder and the second shaft sleeve 15; the grinding spindle 8 is installed inside the movable slider 13 through the first tapered roller bearing 12 and the second tapered roller bearing 14; the first tapered roller bearing 12 and the second tapered roller bearing 14 are positioned by the first flange 11, the second flange 19, the first shaft sleeve 9, and the second shaft sleeve 15; the first flange 11 and the second flange 19 are fixed to the movable slider 13 by the first fastening screw 10 and the second fastening screw 18 respectively; the grinding wheel fastener 5 is installed at the lower end of the grinding spindle 8; the grinding wheel 4 is installed on the grinding wheel fastener 5.

[0047] The atmospheric plasma activation and power structure includes a first servo motor 16, a first servo motor rotating shaft 17, a first coupling 20, a first pulley rotating shaft 21, a first driving pulley 22, a first fastening nut 25, a first synchronous belt 23, a first driven pulley 24, a third shaft sleeve 28, a plasma spray gun 6, a radio frequency power supply coil 7, a third tapered roller bearing 29, a fourth tapered roller bearing 30, a third flange 27, a fourth flange 31, a third fastening screw 26, a fourth fastening screw 32, a gas rotary joint inner sleeve 34, a gas rotary joint outer sleeve 33, an oxidizing gas inlet 50, an inert gas inlet 52, a first sealing ring 49, a second sealing ring 51, a third sealing ring 53, The first deep groove ball bearing 37, the second deep groove ball bearing 46, the fifth flange 35, the sixth flange 42, the fifth fastening screw 36, the sixth fastening screw 43, the second shaft sleeve 38, the third shaft sleeve 39, the seventh flange 45, the seventh fastening screw 44, the fourth shaft sleeve 47, the fifth shaft sleeve 48, the fourth fastening screw 32; the first servo motor 17 is mounted on the moving slider 13; the first pulley rotating shaft 21 is connected to the first servo motor rotating shaft 17 through the first coupling 20; the first driving pulley 22 is fixed to the first pulley rotating shaft 24 through the first fastening nut 25; the first driving pulley 22 and the first driven pulley 24 are driven by the first synchronous belt 23; the The first driven pulley 24 is positioned by the third shaft sleeve 28 and the shoulder of the plasma spray gun 6; a radio frequency power supply coil 7 is arranged between the plasma spray gun 6 and the grinding spindle 8; the plasma spray gun 6 is installed inside the movable slider 13 through the third tapered roller 29 and the fourth tapered roller 30; the third tapered roller 29 and the fourth tapered roller 30 are positioned by the third flange 27, the fourth flange 31, the third shaft sleeve 27, and the inner sleeve 34 of the gas rotary joint; the third flange 27 and the fourth flange 31 are fixed by the third fastening screw 26 and the fourth fastening screw 32 respectively; the inner sleeve 34 of the gas rotary joint is fixed to the upper end of the plasma spray gun 6; the inner sleeve 34 of the gas rotary joint and the gas rotary joint are ... The adapter outer sleeve 33 is provided with an oxidizing gas inlet 50 and an inert gas inlet 52, and is also provided with a first sealing ring 49, a second sealing ring 51, and a third sealing ring 53 to prevent gas leakage; the gas rotary joint inner sleeve 34 and the gas rotary joint outer sleeve 33 are connected through a first deep groove ball bearing 37 and a second deep groove ball bearing 46; the first deep groove ball bearing 37 is positioned through a fifth flange 35, a sixth flange 42, a second shaft sleeve 38, and a third shaft sleeve 39; the second deep groove ball bearing 46 is positioned through a sixth flange 42, a seventh flange 45, a fourth shaft sleeve 47, and a fifth shaft sleeve 48; the sixth flange 42 is fixed to the gas rotary joint inner sleeve 34 by a sixth fastening screw 43;The fifth flange 35 and the seventh flange 45 are fixed to the outer sleeve 33 of the gas rotary joint by the fifth fastening screw 36 and the seventh fastening screw 44 respectively; the outer sleeve 33 of the gas rotary joint is fixed to the moving slider 13 by the fourth fastening screw 32.

[0048] The porous ceramic suction cup 62 in the base and workpiece power structure absorbs the workpiece of 2 to 12 inches; the fourth servo motor 68 drives and controls the workpiece rotating shaft 63 to absorb the workpiece and rotate at a speed of 10 to 150 r / min.

[0049] The second servo motor 41 in the grinding device displacement mechanism drives the lead screw to control the up and down displacement of the grinding spindle 8, so as to achieve an axial feed speed of the grinding spindle 8 of 0.1-10 μm / s.

[0050] The third servo motor 61 in the power structure of the grinding device drives and controls the grinding wheel fastener 5 installed on the grinding spindle 8 to clamp the grinding wheel 4 and rotate at a speed of 1000-3000 r / min. The shape of the grinding wheel 4 is an annular sheet, a circular sheet, a square sheet or a polygonal sheet. The sheet-shaped grinding wheel 4 is arranged in one or more circles.

[0051] The first servo motor 16 in the atmospheric plasma activation and power structure drives and controls the plasma spray gun 6 to rotate at a speed of 10-100 r / min. The plasma spray gun 6 has a single hole or a multi-hole structure, and the shape of the hole is circular, square or polygonal. The RF power supply coil 7 activates the oxidizing gas into plasma through an external RF power supply, wherein the number of coil turns, coil thickness, and RF power supply power are all adjustable.

[0052] The gas rotary joint outer sleeve 33 and the gas rotary joint inner sleeve 34 are provided with a hole or a plurality of porous gas flow channels, and the oxidizing gas is transported to the excitation area of ​​the RF power supply coil 7 through the central pipeline. An inert gas annular groove 85 and an oxidizing gas annular groove 86 are provided between the gas rotary joint outer sleeve 33 and the gas rotary joint inner sleeve 34, so that the stability of the gas inflow is always maintained during the rotation of the gas rotary joint inner sleeve 34; the type, ratio, flow rate, flow rate and pressure of the oxidizing gas and the inert gas are adjusted according to demand.

[0053] The present invention also discloses an atmospheric plasma assisted workpiece self-rotation grinding method, which comprises the following steps:

[0054] 1) According to the structure of the machine tool, an atmospheric plasma-assisted workpiece self-rotation grinding device is designed and adapted;

[0055] 2) Select a suitable grinding wheel 4 and connect it to the grinding wheel fastener 5 through screws, place the grinding wheel 4 dresser on the porous ceramic suction cup 62, and start the porous ceramic suction cup 62; use the tool setting block to set the tool, set the workpiece coordinates, the grinding wheel 4 dressing amount and the z-direction feed speed;

[0056] 3) Start the fourth servo motor 68 to drive the workpiece to rotate at a speed of 10-150 r / min, start the third servo motor 61 to drive the grinding wheel 4 to rotate at a speed of 10-100 r / min, start the second servo motor 41 to make the grinding spindle 8 axially feed at a speed of 0.1-10 μm / s, so that the grinding wheel dresser can correct the removal amount of the grinding wheel 4 by 10μm-50μm;

[0057] 4) After the grinding wheel 4 is corrected, the surface of the workpiece table is cleaned with an oil stone; the workpiece is adsorbed on the porous ceramic suction cup 62, and the workpiece is placed within the grinding range of the grinding device, and the tool is set with a tool setting block, and the working coordinate system, machining allowance and z-direction feed speed are set;

[0058] 5) According to the characteristics of the processing object, select appropriate oxidizing gas and inert gas, and use a suitable radio frequency power supply coil 7 to install it inside the grinding spindle 8;

[0059] 6) Start the gas pump, control the gas velocity, flow rate and pressure, and inject oxidizing gas and inert gas into the plasma spray gun 6 at a certain rate;

[0060] 7) Starting the external RF power supply of the coil, the RF power supply coil 7 is energized to activate the oxidizing gas in the plasma spray gun 6 to form plasma;

[0061] 8) Start the fourth servo motor 68 to drive the workpiece rotating shaft 63 to rotate, so that the workpiece rotating shaft 63 drives the workpiece to rotate at a speed of 50-500 r / min; start the third servo motor 61 to drive the grinding spindle 8 to rotate, so that the grinding wheel 4 clamped on the grinding spindle 8 rotates at a speed of 10-100 r / min; start the first servo motor 16 to drive the plasma spray gun 6 to rotate, so that the plasma spray gun 6 rotates at a speed of 10-100 r / min;

[0062] 9) Start the second servo motor 41 to lower the grinding wheel 4 to a height of 1 to 5 mm from the workpiece, reduce the rotation speed of the second servo motor 41, and make the grinding wheel 4 grind the workpiece surface at an axial feed speed of 0.1 to 10 μm / s; after the hard and brittle material is modified by plasma oxidation, an oxide that is easier to remove is formed on the workpiece surface, and the abrasive group particles can grind the oxide on the workpiece surface efficiently, ultra-smoothly and without damage through the relative movement of the workpiece and the grinding wheel 4.

[0063] In the present invention, the oxidizing gas and the inert gas flow in from the oxidizing gas inlet 50 and the inert gas inlet 52 respectively through the air pump. Since the outer sleeve 33 of the gas rotary joint is provided with the inert gas annular groove 85 and the oxidizing gas annular groove 86 at the oxidizing gas inlet 50 and the inert gas inlet 52, the gas is stably injected into the plasma spray gun 6 during the rotation of the plasma spray gun 6. When the oxidizing gas and the inert gas flow through the plasma activation area, the oxidizing gas is activated under the protection of the inert gas. At the same time, under the action of the self-rotation of the plasma spray gun 6 and the self-rotation of the workpiece rotating shaft 63, the oxidizing gas is uniformly sprayed on the workpiece, so as to realize uniform oxidation of the workpiece surface and form a loose soft modified layer, thereby effectively improving the grinding efficiency and quality. The self-rotation of the grinding spindle 8 drives the grinding wheel fastener 5 to clamp the grinding wheel 4 and the workpiece to rotate relative to each other. The workpiece adsorbed on the workpiece rotating shaft 63 by the porous ceramic suction cup 62 is first uniformly oxidized by the plasma, and then is efficiently removed under the action of relative rotation, so as to have a higher surface quality.

[0064] In summary, the atmospheric plasma-assisted workpiece self-rotation grinding device provided by the present invention can obtain a high-quality workpiece with good surface consistency and no surface and sub-surface damage, and the cost is low, which is very suitable for high-efficiency ultra-smooth and uniform grinding of optical elements. Example 1

[0065] When applying the atmospheric plasma assisted workpiece self-rotation grinding device provided in this embodiment, according to the structure of the machine tool, an atmospheric plasma assisted workpiece self-rotation grinding device is designed and adapted; a suitable grinding wheel 4 is selected and connected to the grinding wheel fastener 5 by screws, and the grinding wheel dresser is placed on the porous ceramic suction cup 62, and the porous ceramic suction cup 62 is started. The tool setting block is used for tool setting, and the coordinates of the workpiece to be processed, the grinding wheel dressing amount and the z-direction feed speed are set; the fourth servo motor 68 is started to drive the workpiece to rotate at a speed of 150 r / min, the third servo motor 61 is started to drive the grinding wheel 4 to rotate at a speed of 100 r / min, and the second servo motor 41 is started to make the grinding 8 spindle axially feed at a speed of 10 μm / s, so that the grinding wheel dresser can correct the grinding wheel 4 by 50 μm removal; after the grinding wheel 4 is corrected, the surface of the workpiece table is cleaned with an oilstone. The workpiece is adsorbed on the porous ceramic suction cup 62, and the workpiece is located within the grinding range of the grinding device. The tool setting block is used to set the tool, and the working coordinate system, machining allowance and z-direction feed speed are set; according to the characteristics of the processing object, suitable oxidizing gas and inert gas are selected, and a suitable radio frequency power supply coil 7 is installed inside the grinding spindle 8; the air pump is started, the gas flow rate, flow rate and pressure are controlled, and the oxidizing gas and inert gas are injected into the plasma spray gun 6 at a certain rate; the external radio frequency power supply of the start coil is turned on, and the radio frequency power supply coil 7 is energized to activate the oxidizing gas in the plasma spray gun 6 to form plasma; the fourth servo motor 68 is started to drive the workpiece rotating shaft 63 to rotate, so that the workpiece rotating shaft 63 drives the workpiece to rotate at a speed of 500 r / min. The third servo motor 61 is started to drive the grinding spindle 8 to rotate, so that the grinding wheel 4 clamped on the grinding spindle 8 rotates at a speed of 100 r / min. The first servo motor 16 is started to drive the plasma spray gun 6 to rotate, so that the plasma spray gun 6 rotates at a speed of 100 r / min. The second servo motor 41 is started to lower the grinding wheel 4 to a height of 5 mm from the workpiece, and the speed of the second servo motor 41 is reduced so that the grinding wheel 4 grinds the workpiece surface at an axial feed speed of 10 μm / s. After the hard and brittle material is modified by plasma oxidation, an oxide that is easier to remove is formed on the workpiece surface. The relative movement between the workpiece and the grinding wheel 4 enables the abrasive group particles to grind the oxide on the workpiece surface efficiently, ultra-smoothly and without damage.

[0066] Under the premise that no conflict occurs, those skilled in the art may freely combine and superimpose the above-mentioned additional technical features.

[0067] The above description is only a preferred implementation mode of the present invention. Any technical solution that achieves the purpose of the present invention by substantially the same means belongs to the protection scope of the present invention.

Claims

1. An atmospheric plasma assisted workpiece self-rotating grinding device, characterized in that: It includes a base and workpiece power structure, a grinding device power structure, an atmospheric plasma activation and power structure, and a grinding device displacement mechanism; The base and workpiece power structure includes a base plate, a convex base plate, an arched bracket, a third pulley rotating shaft, and a workpiece shaft rotating shaft. The convex base plate is fixed to the upper end of the base plate by a ninth fastening screw; the arched bracket is fixed to one side of the base plate; a fourth servo motor is fixed to the convex base plate; the rotating shaft of the fourth servo motor is connected to the rotating shaft of the third pulley by a third coupling; a third driving pulley is fixed to the rotating shaft of the third pulley by a third fastening nut; a third driven pulley is fixed to the rotating shaft of the workpiece by a fourth fastening nut; the third driving pulley and the third driven pulley are driven by a third synchronous belt; a porous ceramic suction cup is fixed to the upper end of the workpiece rotating shaft; the workpiece rotating shaft is installed inside the convex base plate by a fifth tapered roller bearing and a sixth tapered roller bearing; The displacement mechanism of the grinding device includes a moving slider, a screw, a second servo motor, and a rotating shaft of the second servo motor. The moving slider is displaced up and down by the screw. The second servo motor is installed on the upper end of the arch bracket; the screw is connected to the rotating shaft of the second servo motor through a fourth coupling; the screw is positioned by a bearing base; the bearing base is fixed to the arch bracket by an eleventh fastening screw; The power structure of the grinding device includes a grinding spindle, a grinding wheel fastener, a third servo motor, and a second pulley rotating shaft. A grinding wheel is installed on the grinding wheel fastener, and the grinding wheel fastener is installed at the lower end of the grinding spindle. The grinding spindle is installed inside the moving slider through a first tapered roller bearing and a second tapered roller bearing; the third servo motor is fixed on the moving slider; a second driven pulley is fixed on the grinding spindle through a shoulder of the grinding spindle and a second shaft sleeve; a second driving pulley is fixed on the second pulley rotating shaft through a second fastening nut; the second pulley rotating shaft is connected to the third servo motor rotating shaft through a second coupling; the second driving pulley and the second driven pulley are driven by a second synchronous belt; The atmospheric plasma activation and power structure comprises a plasma spray gun, an inner sleeve of a gas rotary joint, an outer sleeve of a gas rotary joint, a first servo motor and a first pulley rotating shaft. The plasma spray gun is installed inside a movable slider through a third tapered roller and a fourth tapered roller; a radio frequency power supply coil is arranged between the plasma spray gun and the grinding spindle; the inner sleeve of the gas rotary joint is fixed to the upper end of the plasma spray gun; the outer sleeve of the gas rotary joint is fixed to the movable slider through a fourth fastening screw; the inner sleeve of the gas rotary joint and the outer sleeve of the gas rotary joint are connected through a first deep groove ball bearing and a second deep groove ball bearing; the first servo motor is installed on the movable slider; the first pulley rotating shaft is connected to the first servo motor rotating shaft through a first coupling; a first driving pulley is fixed to the first pulley rotating shaft through a first fastening nut; the first driving pulley is driven by a first synchronous belt and a first driven pulley; the first driven pulley is positioned through a third shaft sleeve and a plasma spray gun shoulder.

2. The atmospheric plasma assisted workpiece self-rotating grinding device according to claim 1, characterized in that: The porous ceramic suction cup in the base and workpiece power structure adsorbs the workpiece of 2 to 12 inches; the fourth servo motor drives and controls the workpiece rotating shaft to adsorb the workpiece and rotate at a speed of 10 to 150 r / min; the fifth tapered roller bearing and the sixth tapered roller bearing are positioned through the shoulder of the workpiece rotating shaft, the sixth shaft sleeve, the eighth flange and the ninth flange; the eighth flange and the ninth flange are respectively installed on the convex bottom plate through the eighth fastening screw and the tenth fastening screw.

3. The atmospheric plasma assisted workpiece self-rotating grinding device according to claim 1, characterized in that: The second servo motor in the displacement mechanism of the grinding device drives the lead screw to control the up and down displacement of the grinding spindle, thereby achieving an axial feed speed of the grinding spindle in the range of 0.1-10 μm / s.

4. The atmospheric plasma assisted workpiece self-rotating grinding device according to claim 1, characterized in that: The third servo motor in the power structure of the grinding device drives and controls the grinding wheel fastener installed on the grinding spindle to clamp the grinding wheel and rotate at a speed of 1000~3000 r / min. The grinding wheel is in the shape of an annular sheet, a circular sheet, a square sheet or a polygonal sheet, and the sheet grinding wheel is arranged in one or more circles of annular circles; the first tapered roller bearing and the second tapered roller bearing are positioned by the first flange, the second flange, the first shaft sleeve and the second shaft sleeve; the first flange and the second flange are fixed to the movable slider by the first and second fastening screws and the second fastening screws respectively.

5. The atmospheric plasma assisted workpiece self-rotating grinding device according to claim 1, characterized in that: The first servo motor in the atmospheric plasma activation and power structure drives and controls the plasma spray gun to rotate at a speed of 10-100 r / min. The plasma spray gun has a single hole or a multi-hole structure, and the shape of the hole is circular, square or polygonal. The radio frequency power supply coil activates the oxidizing gas into plasma through an external radio frequency power supply, wherein the number of coil turns, coil thickness, and radio frequency power supply power are all adjustable.

6. The atmospheric plasma assisted workpiece self-rotating grinding device according to claim 5, characterized in that: The outer sleeve of the gas rotary joint and the inner sleeve of the gas rotary joint are provided with a single hole or a multi-hole gas flow channel, the oxidizing gas is transported to the excitation area of ​​the RF power supply coil through the central pipeline, and an inert gas annular groove and an oxidizing gas annular groove are provided between the outer sleeve of the gas rotary joint and the inner sleeve of the gas rotary joint, so that the stability of the gas inflow is always maintained during the rotation of the inner sleeve of the gas rotary joint; the type, ratio, flow rate, flow velocity and pressure of the oxidizing gas and the inert gas are adjusted according to demand.

7. The atmospheric plasma assisted workpiece self-rotating grinding device according to claim 1, characterized in that: The third tapered roller bearing and the fourth tapered roller bearing in the atmospheric plasma activation and power structure are positioned by the third flange, the fourth flange, the third shaft sleeve, and the inner sleeve of the gas rotary joint; the third flange and the fourth flange are fixed by the third fastening screw and the fourth fastening screw respectively; the first deep groove ball bearing is positioned by the fifth flange, the sixth flange, the second shaft sleeve, and the third shaft sleeve; the second deep groove ball bearing is positioned by the sixth flange, the seventh flange, the fourth shaft sleeve, and the fifth shaft sleeve; the sixth flange is fixed to the inner sleeve of the gas rotary joint by the sixth fastening screw; the fifth flange and the seventh flange are fixed to the outer sleeve of the gas rotary joint by the fifth fastening screw and the seventh fastening screw respectively.

8. The atmospheric plasma assisted workpiece self-rotating grinding device according to claim 1, characterized in that: The inner sleeve of the gas rotary joint and the outer sleeve of the gas rotary joint are provided with an oxidizing gas inlet and an inert gas inlet. The oxidizing gas inlet is also provided with a first sealing ring, a second sealing ring and a third sealing ring to prevent gas leakage.

9. An atmospheric plasma assisted workpiece self-rotation grinding method, characterized in that: An atmospheric plasma assisted workpiece self-rotation grinding device according to any one of claims 1 to 8, the method comprising the following steps: 1) According to the structure of the machine tool, an atmospheric plasma-assisted workpiece self-rotation grinding device is designed and adapted; 2) Select a suitable grinding wheel and connect it to the grinding wheel fastener through screws, place the grinding wheel dresser on the porous ceramic suction cup, and start the porous ceramic suction cup; use the tool setting block to set the tool, set the workpiece coordinates, grinding wheel dressing amount and z-direction feed speed; 3) Start the fourth servo motor to drive the workpiece to rotate at a speed of 10-150 r / min, start the third servo motor to drive the grinding wheel to rotate at a speed of 10-100 r / min, start the second servo motor to make the grinding spindle axially feed at a speed of 0.1-10 μm / s, and realize the grinding wheel dresser to correct the grinding wheel by 10-50 μm removal; 4) After the grinding wheel is corrected, use an oil stone to clean the surface of the workpiece table; adsorb the workpiece on the porous ceramic suction cup, and make the workpiece located within the grinding range of the grinding device, use the tool setting block to set the tool, set the working coordinate system, machining allowance and z-direction feed speed; 5) According to the characteristics of the processing object, select appropriate oxidizing gas and inert gas, and use a suitable RF power coil to install it inside the grinding spindle; 6) Start the gas pump, control the gas velocity, flow rate and pressure, and inject oxidizing gas and inert gas into the plasma spray gun at a certain rate; 7) Start the external RF power supply of the coil, and energize the RF power supply coil to activate the oxidizing gas in the plasma spray gun to form plasma; 8) Start the fourth servo motor to drive the workpiece rotating shaft to rotate, so that the workpiece rotating shaft drives the workpiece to rotate at a speed of 50~500 r / min; start the third servo motor to drive the grinding spindle to rotate, so that the grinding wheel clamped on the grinding spindle rotates at a speed of 10~100 r / min; start the first servo motor to drive the plasma spray gun to rotate, so that the plasma spray gun rotates at a speed of 10~100 r / min; 9) Start the second servo motor to lower the grinding wheel to a height of 1-5 mm from the workpiece, reduce the speed of the second servo motor, and make the grinding wheel grind the workpiece surface at an axial feed speed of 0.1-10 μm / s; after the hard and brittle materials are modified by plasma oxidation, oxides that are easier to remove are formed on the workpiece surface, and the abrasive group particles can grind the oxides on the workpiece surface efficiently, ultra-smoothly and without damage through the relative motion between the workpiece and the grinding wheel.

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