A milling and grinding combined processing device for silicon carbide material

Abstract

The application discloses a kind of milling and grinding composite processing devices of silicon carbide material, including base, the upper side of base is provided with the moving platform of being driven to left and right translation by first screw rod driving assembly, the upper side of moving platform is provided with the workbench of being driven to front and rear translation by second screw rod driving assembly, support seat is provided with the spindle box of being driven to lift by third screw rod driving assembly, spindle box is installed with tool clamping unit, the lower end of tool clamping unit clamps special milling and grinding tool, the side of base is installed with grinding fluid filter box, the upper side of grinding fluid filter box is installed with plate heat exchanger, the inside of spindle box is provided with several intercommunication cooling flow channel, grinding fluid storage tank is connected with the import of cooling flow channel by hose, the outlet of cooling flow channel is connected with tool clamping unit by pipeline.The present application can solve the problem that the existing wire cutting technology and cylindrical grinding machine process have relatively large limitations for processing silicon carbide material.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of silicon carbide material processing, in particular to a milling and grinding combined processing device for silicon carbide material. BACKGROUND

[0002] The silicon carbide material has high hardness (Mohs hardness 9.2-9.3), and the current processing mode is generally a combination of wire cutting technology and cylindrical grinding machine processing, wherein the processing precision of the wire cutting is low, and the time consumption is long; increasing the cutting efficiency will greatly increase the crystal breaking rate. Since the silicon carbide material has relatively high hardness, it takes a longer time to grind the crystal ingot to the corresponding size. At present, there is no milling and grinding combined special tool for processing equipment that can meet the high-precision processing requirements of high-hardness silicon carbide material. SUMMARY

[0003] The application provides a milling and grinding combined processing device for silicon carbide material, which can solve the problem that the current wire cutting technology and cylindrical grinding machine process have relatively large limitations for processing silicon carbide material.

[0004] To achieve the above object, the application provides the following technical scheme: a milling and grinding combined processing device for silicon carbide material, comprising a base, the upper side of the base is provided with a moving platform driven by a first lead screw transmission assembly to move left and right, the upper side of the moving platform is provided with a workbench driven by a second lead screw transmission assembly to move forward and backward, one side of the base is provided with a support seat, one side of the support seat facing the moving platform is provided with a spindle box driven by a third lead screw transmission assembly to move up and down, the spindle box is installed with a tool clamping unit, the lower end of the tool clamping unit clamps a special milling and grinding tool, the special milling and grinding tool comprises a thin-walled cylinder, a metal powder sintered grinding wheel arranged at the open end of the thin-walled cylinder and a tool holder arranged at the closed end of the thin-walled cylinder, the tool holder is provided with a grinding fluid injection hole pointing to the metal powder sintered grinding wheel, one side of the base is installed with a grinding fluid filter box, the upper side of the grinding fluid filter box is installed in communication with a plate heat exchanger, the inside of the support seat is installed with a grinding fluid storage tank connected with the plate heat exchanger through a pipeline, the inside of the spindle box is provided with a plurality of connected cooling flow channels, the grinding fluid storage tank is connected with the inlet of the cooling flow channel through a hose, and the outlet of the cooling flow channel is connected with the tool clamping unit through a pipeline. The special tool combining the metal powder sintered grinding wheel and the thin-walled cylinder can quickly cool the processing position, improve the processing precision, the grinding fluid flowing through the spindle box can quickly take away the heat generated in the use process of the spindle box, reduce the thermal expansion deformation of the spindle box, ensure the processing precision of the silicon carbide material, and the plate heat exchanger can keep the low temperature of the grinding fluid entering the spindle box, and improve the cooling effect.

[0005] As preferred, the main shaft box has multiple hollow cavities inside, and the cooling flow channel is arranged along the side wall of the hollow cavity. The hollow cavity can improve the strength of the main shaft box, and the individual hollow cavity can also be used to install the main shaft, motor and other components. The cooling flow channel arranged along the hollow cavity can improve the cooling effect of these components.

[0006] As preferred, the hollow cavity is tightly filled with a plurality of rubber damping balls. The rubber damping balls utilize elastic deformation and internal friction loss to vibrate energy, which is particularly effective for high-frequency vibrations commonly seen in milling and grinding processes. When the main shaft box vibrates, the mutual extrusion, friction and self-deformation between the damping balls can convert the vibration energy into heat energy, reducing the vibration amplitude by 40-70%. The heat energy can be taken away by the cooling flow channel.

[0007] As preferred, the upper side of the base is provided with a first oil-proof organ cover on both sides of the moving platform to shield the first lead screw transmission assembly. The first oil-proof organ cover is arranged obliquely to one side. The base is provided with a backflow pipe extending to the grinding fluid filter box at a position matching the oblique direction of the first oil-proof organ cover. The oblique arrangement of the oil-proof organ cover can guide the grinding fluid, debris and other impurities to slide quickly along the inclined surface, avoiding accumulation on the surface of the organ cover, reducing the frequency of manual cleaning, improving the stability of long-term operation of the equipment, and solving the problems of protection of transmission components and recycling of grinding fluid in silicon carbide processing, with reliability, cleanliness and economy.

[0008] As preferred, one side of the support seat is provided with a second oil-proof organ cover shielding the third lead screw transmission assembly and extending and retracting with the main shaft box. The upper side of the moving platform is provided with a third oil-proof organ cover on both sides of the workbench to shield the second lead screw transmission assembly. Similarly, the second and third oil-proof organ covers can improve the protection of the third and second lead screw transmission assemblies.

[0009] As preferred, the grinding fluid filter box includes multiple adjacent flow-through bins connected by flow-through holes with heights decreasing in sequence. The bottom of the flow-through bin is provided with an inclined bottom surface, both ends of which are lower than the connected flow-through holes. The top of the flow-through bin corresponding to the backflow pipe is provided with a liquid inlet, and at least one layer of filter screen is arranged on the liquid inlet. Through the combined design of multi-layer filter screen, gradient bin body gravity sedimentation and inclined bottom surface impurity collection, the problem of easy contamination of grinding fluid by fine particles in silicon carbide processing is solved, ensuring the stability of cooling and lubrication effect, and finally improving the processing precision and equipment life.

[0010] As preferred, the joint surface between the metal powder sintered grinding wheel and the thin-walled cylinder is a zigzag joint surface, which significantly improves the connection strength of the grinding wheel and the thin-walled cylinder by increasing the contact area and mechanical interlocking structure, avoids radial or axial displacement or even shedding of the grinding wheel during high-speed rotation or under force, and ensures the safety and stability of processing.

[0011] As preferred, a plurality of reinforcing rib plates are arranged on the inner side wall of the thin-walled cylinder around the circumference, and the height of the reinforcing rib plates gradually increases from one end close to the metal powder sintered grinding wheel to the other end. The gradually changing rib plate height design can make the load smoothly transmit along the axial direction of the thin-walled cylinder, avoiding stress concentration caused by sudden change of rib plate height. Especially under high-speed rotating working condition, the distribution difference of centrifugal force along the axial direction can be effectively balanced by the gradually changing characteristics of the rib plate height, improving the structural fatigue life.

[0012] As preferred, reinforcing ribs are arranged inside the support seat and the base in horizontal and vertical staggered manner, which can increase the rigidity of the whole device and reduce vibration during processing.

[0013] As preferred, sheet metal baffles are arranged on the upper side of the base along the edge, and double doors are arranged on the side of the sheet metal baffles away from the support seat.

[0014] Compared with the prior art, the present application has the following advantages:

[0015] The special tool for combining the metal powder sintered grinding wheel and the thin-walled cylinder can quickly cool the processing position, improve the processing precision, and the heat generated during use of the spindle box can be quickly taken away by the grinding fluid flowing through the spindle box, reducing the thermal expansion deformation of the spindle box and ensuring the processing precision of the silicon carbide material. The plate heat exchanger can maintain the low temperature of the grinding fluid entering the spindle box, improving the cooling effect. The long service life of the metal powder sintered grinding wheel reduces the frequency of tool replacement. The large capacity design and automatic backwashing function of the grinding fluid filter box reduce the frequency of manual liquid replacement and the waste of consumables. The integrated design of the cooling flow channel and the grinding fluid circulation reduces the failure points of external pipeline connection and improves the reliability of long-term operation of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is the overall perspective structure diagram of the present application;

[0017] Figure 2 It is the perspective structure diagram of the present application after removing the sheet metal baffles;

[0018] Figure 3 It is the front view and sectional structure diagram of the present application after removing the sheet metal baffles;

[0019] Figure 4 It is the side view and sectional structure diagram of the present application after removing the sheet metal baffles;

[0020] Figure 5 Fig. 1 is a schematic view of a local structure of the application;

[0021] Figure 6 Fig. 2 is a schematic view of a main structure of a special milling cutter of the application.

[0022] Reference signs:

[0023] 1, base, 10, motor, 11, third screw transmission assembly, 12, moving platform, 13, special milling cutter, 131, thin-walled cylinder, 132, metal powder sintered grinding wheel, 133, sawtooth joint surface, 134, reinforcing rib plate, 135, grinding fluid injection hole, 137, tool shank, 14, cutter clamping unit, 15, rubber damping ball, 16, liquid pump, 17, grinding fluid storage tank, 18, plate heat exchanger, 19, grinding fluid filter tank, 191, filter screen, 192, inclined bottom surface, 193, flow-through bin, 2, sheet metal baffle, 20, cooling flow channel, 21, first screw transmission assembly, 22, reinforcing rib, 23, return pipe, 24, third oil-proof concertina cover, 3, double-door, 4, workbench, 5, second screw transmission assembly, 6, support seat, 7, main shaft box, 8, second oil-proof concertina cover, 9, first oil-proof concertina cover. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application.

[0025] As Figures 1-6As shown, in order to solve the problem that the existing wire cutting technology and the outer circle grinding machine process have relatively large limitations for processing silicon carbide material in the embodiment, a milling and grinding composite processing device for silicon carbide material is provided, which comprises a base 1, the upper side of the base 1 is provided with a moving platform 12 driven by a first screw rod transmission assembly 21 to move left and right, the upper side of the moving platform 12 is provided with a workbench 4 driven by a second screw rod transmission assembly 5 to move forward and backward, one side of the base 1 is provided with a supporting seat 6, one side of the supporting seat 6 facing the moving platform 12 is provided with a spindle box 7 driven by a third screw rod transmission assembly 11 to lift, the spindle box 7 is installed with a tool clamping unit 14, the lower end of the tool clamping unit 14 clamps a special milling and grinding tool 13, the special milling and grinding tool 13 comprises a thin-walled cylinder 131, a metal powder sintered grinding wheel 132 arranged at the opening end of the thin-walled cylinder 131 and a tool holder 137 arranged at the closed end of the thin-walled cylinder 131, the tool holder 137 is provided with a grinding fluid injection hole 135 pointing to the metal powder sintered grinding wheel 132, one side of the base 1 is installed with a grinding fluid filtering box 19, the upper side of the grinding fluid filtering box 19 is communicated and installed with a plate heat exchanger 18, the inside of the supporting seat 6 is installed with a grinding fluid storage box 17 connected with the plate heat exchanger 18 through a pipeline, the inside of the spindle box 7 is provided with a plurality of connected cooling flow channels 20, the grinding fluid storage box 17 is connected with the inlet of the cooling flow channel 20 through a hose, and the outlet of the cooling flow channel 20 is connected with the tool clamping unit 14 through a pipeline. By setting the special tool combining the metal powder sintered grinding wheel and the thin-walled cylinder, the machining position can be quickly cooled, the machining precision is improved, the heat generated by the spindle box 7 during use can be quickly taken away by the grinding fluid flowing through the spindle box 7, the thermal expansion and deformation of the spindle box 7 are reduced, the machining precision of the silicon carbide material is ensured, and the plate heat exchanger 18 can keep the grinding fluid entering the spindle box 7 low temperature, improving the cooling effect.

[0026] Specifically, silicon carbide has high hardness (Mohs hardness 9.2-9.3), and traditional grinding wheels (such as resin-based diamond grinding wheels) are prone to cause processing efficiency to decrease and precision deviation due to abrasive particle shedding or binder wear during high-speed milling and grinding. Therefore, in the embodiment, a metal powder sintered grinding wheel 132 is used as a cutting / grinding component, which utilizes the high wear resistance of the metal binder and the strong holding force for abrasive particles (such as diamond micro powder), significantly improving the service life of the grinding wheel, reducing the frequency of frequent tool replacement, and reducing the processing cost. Moreover, the metal powder sintered grinding wheel 132 is integrally sintered with the thin-walled cylinder 131, avoiding the mechanical connection loosening problem of traditional grinding wheels and tool holders, ensuring the structural stability during high-speed rotation, and reducing the processing surface defects (such as chatter marks and edge cracking) caused by vibration.

[0027] In addition, the high heat generated by the friction between the metal powder sintered grinding wheel 132 and the silicon carbide material during milling and grinding can reach a local temperature of more than 1000°C, which can easily lead to thermal failure of the grinding wheel grains (such as diamond carbonization) and thermal damage to the workpiece surface (such as oxidation layer and lattice distortion). Therefore, the tool holder 137 is provided with a grinding fluid injection hole 135, which is arranged obliquely and can be arranged in 3-4 according to the needs, and directly sprays cooling fluid to the contact area between the grinding wheel and the workpiece to achieve point cooling, quickly take away the friction heat, and inhibit the high-temperature wear of the grinding wheel and the thermal deformation of the workpiece.

[0028] Specifically, the tool clamping unit 14 is a tool clamping device on a conventional machining center, which can be a three-jaw chuck or a taper chuck. The cooling channel 20 is connected to the inside of the tool clamping unit 14 through the pipeline inside the spindle box 7 or the external hose. When the special milling and grinding tool 13 rotates at high speed, the grinding fluid can also be continuously delivered to the grinding fluid injection hole 135.

[0029] Further, silicon carbide is brittle, and excessive cutting force (especially radial force) during milling and grinding can cause edge collapse or subsurface cracks. Traditional rigid tools may amplify stress concentration due to vibration. Therefore, the special milling and grinding tool 13 in this embodiment is designed as a thin-walled cylinder 131 to absorb part of the machining vibration by using the elastic deformation characteristics, reduce the dynamic stress transmitted to the workpiece, and reduce the generation of micro-cracks.

[0030] Moreover, in this embodiment, the XYZ-axis linear motion of the moving platform 12, the workbench 4, and the spindle box 7 realizes the compound motion of the milling and grinding tool (such as plane milling and profile grinding), which can be used for low-stress cutting of complex shapes of silicon carbide workpieces (such as wafer edge chamfering and groove machining), avoiding stress concentration areas in traditional single-axis machining.

[0031] In the prior art, the high thermal conductivity of silicon carbide causes the rapid transfer of processing heat to the spindle system, causing spindle thermal expansion deformation (such as axial thermal elongation > 10 pm), which destroys the processing precision, and the high temperature affects the lubrication performance of the grinding fluid. The spindle box 7 is internally integrated with a cooling flow channel 20, which takes away the heat of the spindle box and the main heat generating components through the circulation of low temperature grinding fluid (such as 20 ± 1 ℃), controls the spindle temperature rise ≤ 5 ℃, and ensures the positional accuracy (such as radial runout ≤ 5 pm) during high speed rotation. The grinding fluid storage tank 17 and the grinding fluid filtration tank 19 are connected in series, and multi-stage filtration is used to remove grinding dust (SiC particles) and metal powder shed by the grinding wheel, to avoid impurities being sprayed into the processing area with the cooling liquid, causing scratches (defect size > 10 pm) on the workpiece surface. The grinding fluid is relatively clean after sufficient filtration by the grinding fluid filtration tank 19, and enters the plate heat exchanger 18 for heat exchange without clogging the plate heat exchanger 18. The plate heat exchanger 18 can be externally connected to cooling water, which can quickly reduce the temperature of the grinding fluid, so the low temperature of the grinding fluid entering the spindle box 7 can be maintained, and the cooling effect can be improved. Liquid pumps 16 can be installed on the pipelines between the plate heat exchanger 18 and the grinding fluid storage tank 17, and between the grinding fluid storage tank 17 and the cooling flow channel 20, to provide circulating power. Since the grinding fluid storage tank 17 and the cooling flow channel 20 of the spindle box 7 are connected by a hose, the lifting of the spindle box 7 will not affect the grinding fluid in the grinding fluid storage tank 17 entering the cooling flow channel 20, and will not interfere.

[0032] In the present embodiment, as shown in Figure 3 The inside of the spindle box 7 has a plurality of hollow cavities, and the cooling flow channel 20 is arranged along the side wall of the hollow cavity. The hollow cavity can improve the strength of the spindle box 7, and individual hollow cavities can also be used to install the tool clamping unit 14, the motor 10 and other components. The cooling flow channel 20 arranged along the hollow cavity can improve the cooling effect of these components. Specifically, the hollow cavity can have various structures. The hollow cavity reduces the weight of the spindle box (weight reduction 15%-20%) while maintaining the rigidity of the spindle box (bending stiffness ≥ 100 N / pm) through the design of the reinforcing ribs on the side wall (such as setting a support rib with a thickness of 3-5 mm between the hollow cavities), to avoid processing vibration caused by structural deformation.

[0033] Meanwhile, in order to improve the damping effect, the hollow inner cavity is tightly filled with a plurality of rubber damping balls 15. The rubber damping balls 15 utilize elastic deformation and internal friction loss to vibrate energy, and the effect is particularly significant for high-frequency vibrations commonly seen in milling and grinding processes. When the spindle box vibrates, the mutual extrusion, friction and self-deformation between the damping balls can convert the vibration energy into heat energy, reducing the vibration amplitude by 40%-70%. The heat energy can be carried away by the cooling channel 20. In addition, by adjusting the density (filling rate 60%-80%) and rubber hardness (Shore hardness 40-60A) of the rubber damping balls 15, the natural frequency of the spindle box 7 can be increased from the traditional solid structure of 150Hz to 250-300Hz, avoiding the typical excitation frequency of milling and grinding (such as 200Hz, corresponding to the 60th harmonic of the grinding wheel speed of 12,000rpm), and suppressing resonance from the source.

[0034] The rubber damping balls 15 act as elastic media, forming a flexible support in the hollow inner cavity, reducing the rigid vibration transmission between the spindle box and the support seat 6, and the screw transmission assembly. For example, when the workbench 4 produces a 5μm periodic vibration due to the screw pitch error, the vibration amplitude transmitted to the spindle after attenuation by the damping balls is ≤1μm, avoiding the vibration-induced processing surface waviness defects (the groove depth is reduced from 50nm in the traditional structure to below 10nm).

[0035] The isotropic damping effect of the rubber material of the rubber damping balls 15 can simultaneously suppress XYZ three-axis vibration, especially for the sensitive radial vibration (affecting surface roughness) and axial vibration (affecting processing depth precision) in silicon carbide processing, achieving balanced control and ensuring that the relative displacement of the grinding wheel and the workpiece contact area is ≤2μm.

[0036] In the embodiment, the upper side of the base 1 is provided with a first oil-proof organ cover 9 on both sides of the moving platform 12 to shield the first lead screw transmission assembly 21. The first oil-proof organ cover 9 is arranged obliquely to one side. The base 1 is provided with a backflow pipe 23 extending to the grinding fluid filtering box 19 at a position matching the oblique direction of the first oil-proof organ cover 9. The oblique arrangement of the oil-proof organ cover can guide the grinding fluid, debris and other impurities to slide quickly along the inclined surface, avoiding accumulation on the surface of the organ cover, reducing the frequency of manual cleaning, improving the stability of long-term operation of the equipment, solving the problems of protection of the transmission components and recycling of the grinding fluid in the silicon carbide processing, and having reliability, cleanliness and economy. Specifically, the first lead screw transmission assembly 21 is responsible for driving the moving platform 12 to translate left and right, which is the key transmission component of the equipment. A large amount of grinding fluid (containing abrasive particles, debris) and oil stains will be generated during the processing of silicon carbide. If the lead screw is directly contacted, it is easy to cause wear and tear of the lead screw, lubrication failure, even jam, affecting the transmission precision and the service life of the equipment. Therefore, the first oil-proof organ cover 9 can prevent the grinding fluid from contacting the first lead screw transmission assembly 21. In addition, the first oil-proof organ cover 9 is arranged obliquely, which can guide the grinding fluid, debris and other impurities to slide quickly along the inclined surface, avoiding accumulation on the surface of the organ cover, reducing the frequency of manual cleaning, and improving the stability of long-term operation of the equipment. The backflow pipe 23 on the base matches the oblique direction of the first oil-proof organ cover 9, which can directly introduce the sliding grinding fluid into the grinding fluid filtering box 19, forming a closed loop system of "protection-recycling-filtering-circulation". The inclination angle of the first oil-proof organ cover 9 is designed to be 30°-45°, so that the grinding fluid slides quickly under the action of gravity, avoiding liquid accumulation. The bottom edge of the first oil-proof organ cover 9 is provided with a 1-2mm high flow guide lip, which guides the liquid to gather in the direction of the backflow pipe 23. As a supplementary scheme, a layer of 20-50 mesh stainless steel filter screen can be pasted inside the inclined surface of the first oil-proof organ cover 9, which can intercept the silicon carbide debris with a diameter greater than 0.5mm, avoiding the blockage of large particle impurities into the backflow pipe. The filter screen edge is connected with the organ cover through magic tape or detachable buckle, which is convenient for regular cleaning.

[0037] In addition, one side of the support seat 6 is provided with a second oil-proof organ cover 8 shielding the third lead screw transmission assembly 11 and stretching and contracting with the spindle box 7. The upper side of the moving platform 12 is provided with a third oil-proof organ cover 24 shielding the second lead screw transmission assembly 5 on both sides of the workbench 4. Similarly, the second oil-proof organ cover 8 and the third oil-proof organ cover 24 can improve the protection of the third lead screw transmission assembly 11 and the second lead screw transmission assembly 5. Among them, the first oil-proof organ cover 9, the second oil-proof organ cover 8 and the third oil-proof organ cover 24 can adopt oil-resistant and wear-resistant butyl rubber or polyurethane fiber composite material with a thickness of 3-5mm, which has flexibility and tear resistance.

[0038] In the embodiment, the grinding fluid filtering box 19 comprises a plurality of adjacent flow-through chambers 193, which are connected through flow-through holes with a height difference in sequence. The bottom of the flow-through chamber 193 is provided with an inclined bottom surface 192, and both ends of the inclined bottom surface 192 are lower than the connected flow-through holes. The top of the flow-through chamber 193 corresponding to the return pipe 23 is provided with a liquid inlet, and at least one layer of filter screen 191 is arranged on the liquid inlet. Through the combined design of multi-layer filter screen preliminary filtration, gradient chamber body gravity sedimentation and inclined bottom surface impurity collection, the problem of easy pollution of grinding fluid by fine particles in silicon carbide processing is solved, the stability of cooling and lubricating effect is ensured, and finally the processing precision and equipment life are improved. Specifically, the filter screen 191 can first filter larger silicon carbide debris, metal swarf and the like, so as to avoid entering the subsequent flow-through chamber and reduce the subsequent sedimentation burden. The adjacent flow-through chambers 193 are connected through flow-through holes with a height difference in sequence. When the grinding fluid flows from the high chamber to the low chamber, the flow rate slows down, and the particle impurities are stratified and deposited due to gravity. That is, larger particles are first deposited in the first flow-through chamber, and fine particles continue to be deposited in the next chamber body along with the liquid. This gradient filtration can efficiently separate impurities of different particle sizes, especially submicron particles generated in silicon carbide processing (such as broken SiC powder). The two ends of the inclined bottom surface 192 at the bottom of each flow-through chamber 193 are lower than the flow-through holes, so that the deposited impurities naturally gather towards the lowest point of the chamber bottom, avoiding the liquid flowing to stir up the impurities again, and facilitating centralized cleaning (such as being discharged through a blowdown valve). Therefore, the silicon carbide has high hardness (Mohs hardness 9.5), and the debris generated during processing is sharp and fine. If not effectively filtered, it is easy to block the grinding fluid injection hole 135, the cooling flow channel 20 or the grinding wheel pore, resulting in insufficient cooling and accelerated tool wear. The structure ensures the cleanliness of the returned grinding fluid through multi-stage filtration and sedimentation, maintains the injection pressure and cooling effect, prolongs the tool life and improves the processing precision.

[0039] As a specific embodiment of the grinding fluid filtering box 19, the number of flow-through chambers is 3 (which can be increased or decreased according to the processing precision requirement), and the material is stainless steel (corrosion resistant, suitable for water-based grinding fluid). The chamber body size is in sequence: the first chamber (liquid inlet chamber): length x width x height = 500mm x 300mm x 400mm, the top liquid inlet is provided with two layers of filter screen (191) (the first layer is 200 mesh coarse filter, and the second layer is 500 mesh fine filter); the second chamber: length x width x height = 500mm x 300mm x 350mm, which is connected with the first chamber through a flow-through hole with a diameter of 50mm and a height difference of 50mm; the third chamber (liquid outlet chamber): length x width x height = 500mm x 300mm x 300mm, which is connected with the second chamber through a flow-through hole with a diameter of 40mm and a height difference of 50mm. The inclined angle of the inclined bottom surface at the bottom of each chamber is 15°, and both ends are lower than the bottom edge of the flow-through hole by 10mm. The lowest point is provided with a DN25 blowdown valve, and the blowdown valve is provided with a ball valve for convenient periodic deslagging.

[0040] In this embodiment, the joint surface between the metal powder sintered grinding wheel 132 and the thin-walled cylinder 131 is a sawtooth joint surface 133. Silicon carbide has high hardness (Mohs hardness 9.2~9.3) and high brittleness, and the grinding wheel needs to bear high-frequency impact load and centrifugal force during milling and grinding. The sawtooth joint surface 133 significantly improves the connection strength of the grinding wheel and the thin-walled cylinder by increasing the contact area (compared with a flat joint) and mechanical interlocking structure, avoiding radial or axial displacement or even falling of the grinding wheel during high-speed rotation or stress, and ensuring the safety and stability of processing. Traditional flat joint is prone to interface cracking due to stress concentration, and the sawtooth structure can disperse the load to multiple tooth surfaces through the gradient transition of the tooth shape, reduce the local stress peak, and prolong the overall life of the tool. In addition, the locking effect of the tooth peaks and valleys of the sawtooth joint surface 133 can offset part of the radial separation trend caused by centrifugal force, especially when the grinding wheel rotates at high speed (such as 10,000~30,000 rpm), the mechanical interlocking effect can effectively inhibit the interface slip. From the perspective of process forming, the sawtooth groove of the metal powder sintered grinding wheel can be directly formed by the mold during forming, so that the grinding wheel material is embedded in the tooth-shaped structure of the thin-walled cylinder to realize the double fixation of metallurgical bonding and mechanical bonding, and avoid the complex process of subsequent gluing or mechanical fastening.

[0041] As an example of the sawtooth joint surface 133: process the sawtooth joint surface 133 on the top end face of the thin-walled cylinder 131, the tooth depth is 1.5~3mm, the tooth pitch is 2~4mm, the tooth angle is 60°~90°, the grooves are evenly distributed along the circumference, and the number is 12~24 teeth. The metal powder sintered grinding wheel 132 fills the preformed blank into the trapezoidal groove of the thin-walled cylinder before sintering, and forms a composite interface of metallurgical bonding and mechanical interlocking between the grinding wheel material (such as bronze-based, resin-based or diamond powder) and the thin-walled cylinder through powder metallurgy sintering process (such as vacuum sintering, temperature 800~1200℃).

[0042] In the embodiment, the inner side wall of the thin-walled cylinder 131 is provided with a plurality of reinforcing ribs 134 around the circumference, the height of the reinforcing ribs 134 gradually increases from one end close to the metal powder sintered grinding wheel 132 to the other end, the thin-walled cylinder 131 is prone to radial or axial deformation when rotating at high speed or bearing grinding load due to the thin wall thickness. The reinforcing ribs 134 are uniformly distributed along the circumference, which can significantly improve the bending and torsional stiffness of the cylinder wall. The height of the reinforcing ribs 134 gradually increases from one end close to the grinding wheel to the other end, which conforms to the principle of stress gradient distribution: the load close to the grinding wheel end (directly bearing the grinding force) is mainly in the form of local contact stress, and the required rib height is relatively low to meet the stiffness requirement; the other end away from the grinding wheel may bear the cumulative effect of bending moment or centrifugal force, and the overall stiffness is compensated by higher ribs to avoid overall bending or instability of the thin-walled cylinder. For example: 8 rectangular ribs are uniformly distributed along the circumference, the rib width is 10mm, and the thickness is 2mm; the rib height close to the grinding wheel end is h1=8mm, the rib height away from the grinding wheel end is h2=15mm, and the middle part is linearly graded (h(x)=8+7x / 200, x is the axial distance, unit: mm); the rib extends linearly along the axial direction, the inner surface is integrally formed with the inner wall of the thin-walled cylinder, and the outer surface avoids the interference with the serrated joint surface 133 area of the metal powder sintered grinding wheel 132.

[0043] In the embodiment, the support seat 6 and the base 1 are both provided with transversely and vertically staggered reinforcing ribs 22, which can increase the stiffness of the entire device and reduce vibration during processing.

[0044] The upper side of the base 1 is provided with a metal sheet baffle 2 along the edge, and the side away from the support seat 6 is provided with a double-door 3.

[0045] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, motion condition, etc. between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications will also change accordingly.

[0046] In addition, the description such as "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0047] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium, can be internal communication of two elements or interaction relationship of two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0048] In addition, the technical solutions among various embodiments of the present application can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor is it within the protection scope required by the present application.

Claims

1. A milling and grinding composite processing device for silicon carbide materials, comprising a base, a movable platform driven by a first screw transmission assembly for left and right translation is provided on the upper side of the base, a workbench driven by a second screw transmission assembly for front and back translation is provided on the upper side of the movable platform, a support seat is provided on one side of the base, and a spindle box driven by a third screw transmission assembly for lifting and lowering is provided on the side of the support seat facing the movable platform, characterized in that: The main shaft box is provided with a tool clamping unit, the lower end of the tool clamping unit clamps a special milling and grinding tool, the special milling and grinding tool comprises a thin-walled cylinder, a metal powder sintered grinding wheel arranged at the open end of the thin-walled cylinder and a tool holder arranged at the closed end of the thin-walled cylinder, the tool holder is provided with a grinding fluid injection hole pointing to the metal powder sintered grinding wheel, one side of the base is provided with a grinding fluid filter box, the upper side of the grinding fluid filter box is provided with a plate heat exchanger in communication, the inside of the support base is provided with a grinding fluid storage tank connected with the plate heat exchanger through a pipeline, the grinding fluid storage tank is connected in series with the grinding fluid filter box, and multi-stage filtration is adopted to remove grinding dust and metal powder falling off from the grinding wheel, so that impurities are prevented from being sprayed into the machining area with the cooling liquid, the grinding fluid filter box comprises a plurality of adjacent flow-through bins, the adjacent flow-through bins are connected in communication through flow-through holes with heights decreasing in sequence, the bottom of the flow-through bin is provided with an inclined bottom surface, both ends of the inclined bottom surface are lower than the connected flow-through holes, the top of the flow-through bin corresponding to the return pipe is provided with a liquid inlet, and at least one layer of filter screen is arranged on the liquid inlet.

2. The apparatus for milling and grinding composite machining of silicon carbide material according to claim 1, characterized by: The inside of the main shaft box is provided with a plurality of cooling flow channels connected in communication, the grinding fluid storage tank is connected with the inlet of the cooling flow channel through a hose, the outlet of the cooling flow channel is connected with the tool clamping unit through a pipeline, the integrated cooling flow channel in the main shaft box controls the temperature rise of the main shaft to be less than or equal to 5 DEG C through low-temperature grinding fluid, and the position accuracy during high-speed rotation is ensured.

3. The apparatus of claim 2, wherein: The inside of the main shaft box has a plurality of hollow cavities, the cooling flow channel is arranged along the side wall of the hollow cavity, and a plurality of rubber damping balls are tightly filled in the hollow cavity.

4. The apparatus for milling and grinding of silicon carbide material according to any one of claims 1 to 3, characterized in that: The upper side of the base is provided with a first oil-proof organ cover shielding the first lead screw transmission assembly on both sides of the moving platform, the first oil-proof organ cover is arranged to be inclined to one side, and the base is provided with a return pipe extending to the grinding fluid filter box at a position matching the inclination direction of the first oil-proof organ cover.

5. The apparatus of claim 1, wherein: One side of the support base is provided with a second oil-proof organ cover shielding the third lead screw transmission assembly and telescoping with the lifting of the main shaft box, and the upper side of the moving platform is provided with a third oil-proof organ cover shielding the second lead screw transmission assembly on both sides of the workbench.

6. The apparatus of any one of claims 1-3, wherein: The joint surface between the metal powder sintered grinding wheel and the thin-walled cylinder is a zigzag joint surface.

7. The apparatus of any one of claims 1-3, wherein: A plurality of reinforcing rib plates are arranged on the inner side wall of the thin-walled cylinder in a circumferential direction, and the height of the reinforcing rib plate gradually increases from one end close to the metal powder sintered grinding wheel to the other end. The inside of the support base and the base is provided with horizontally and vertically staggered reinforcing ribs. The upper side of the base is provided with a metal plate baffle along the edge, and the metal plate baffle is provided with a double-door on the side away from the support base.

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