Milling and grinding combined machining device for silicon carbide material

Abstract

The invention discloses a silicon carbide material milling and grinding combined machining device which comprises a base, the upper side of the base is provided with a moving platform driven by a first lead screw transmission assembly to horizontally move left and right, and the upper side of the moving platform is provided with a workbench driven by a second lead screw transmission assembly to horizontally move front and back. A spindle box driven by a third lead screw transmission assembly to ascend and descend is arranged on the supporting seat, a cutter clamping unit is installed on the spindle box, a special milling and grinding cutter is clamped at the lower end of the cutter clamping unit, a grinding fluid filtering box is installed on one side of the base, and a plate heat exchanger is installed on the upper side of the grinding fluid filtering box in a communicating mode. A plurality of communicated cooling flow channels are arranged in the spindle box, the grinding fluid storage box is connected with inlets of the cooling flow channels through hoses, and outlets of the cooling flow channels are communicated with the tool clamping unit through pipelines. The method can solve the problem that an existing linear cutting technology and a cylindrical grinding machine technology have large limitation on silicon carbide material machining.

Description

Technical Field

[0001] The invention relates to the technical field of silicon carbide material processing, in particular to a milling and grinding composite processing device for silicon carbide material. Background Art

[0002] Silicon carbide materials have high hardness (Mohs hardness 9.2-9.3). The current processing method is generally a combination of wire cutting technology and cylindrical grinding. Wire cutting has low processing accuracy and takes a long time. Improving cutting efficiency will greatly increase the crystal breakage rate. Since silicon carbide materials have a relatively high hardness, it takes longer to grind the ingot to the corresponding size. At present, there is no processing equipment that can meet the high-precision processing requirements of high-hardness silicon carbide materials. Special milling and grinding composite tools. Summary of the invention

[0003] The invention provides a milling and grinding composite processing device for silicon carbide materials, which can solve the problem that the existing wire cutting technology and cylindrical grinding machine process have relatively large limitations in processing silicon carbide materials.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a milling and grinding composite processing device for silicon carbide materials, comprising a base, a movable platform driven by a first screw transmission assembly to translate left and right is arranged on the upper side of the base, a workbench driven by a second screw transmission assembly to translate forward and backward is arranged on the upper side of the movable platform, a support seat is arranged on one side of the base, a spindle box driven by a third screw transmission assembly to lift and lower is arranged on the side of the support seat facing the movable platform, a tool clamping unit is installed on the spindle box, a special milling and grinding tool is clamped at the lower end of the tool clamping unit, and the special milling and grinding tool is The tool comprises a thin-walled tube, a metal powder sintered grinding wheel arranged at the open end of the thin-walled tube, and a tool handle arranged at the closed end of the thin-walled tube, wherein the tool handle is provided with a grinding fluid injection hole pointing to the metal powder sintered grinding wheel, a grinding fluid filter box is installed on one side of the base, a plate heat exchanger is installed on the upper side of the grinding fluid filter box, a grinding fluid storage box connected to the plate heat exchanger through a pipeline is installed inside the support seat, a plurality of interconnected cooling channels are arranged inside the spindle box, the grinding fluid storage box is connected to the inlet of the cooling channel through a hose, and the outlet of the cooling channel is connected to the tool clamping unit through a pipeline. By providing a special tool combining the metal powder sintered grinding wheel with the thin-walled tube, the processing position can be quickly cooled, thereby improving the processing accuracy, the grinding fluid flowing through the spindle box can quickly take away the heat generated by the spindle box during use, reduce the thermal expansion deformation of the spindle box, and ensure the processing accuracy of the silicon carbide material, and the plate heat exchanger can maintain the low temperature of the grinding fluid entering the spindle box, thereby improving the cooling effect.

[0005] Preferably, there are multiple hollow inner cavities inside the spindle box, and the cooling channels are arranged along the side walls of the hollow inner cavities. The hollow inner cavities can improve the strength of the spindle box, and individual hollow inner cavities can also be used to install the spindle, motor and other components. Arranging the cooling channels along the hollow inner cavities can improve the cooling effect on these components.

[0006] Preferably, a number of rubber damping balls are tightly filled in the hollow inner cavities. The rubber damping balls use elastic deformation and internal friction to dissipate vibration energy, especially effective for the high-frequency vibrations common 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 taken away by the cooling channels.

[0007] Preferably, on the upper side of the base and on both sides of the moving platform, there is a first oil-proof bellows cover that shields the first lead screw drive assembly. The first oil-proof bellows cover is inclined to one side. At a position on the base that matches the inclination direction of the first oil-proof bellows cover, there is a return pipe extending to the grinding fluid filtration tank. The inclined oil-proof bellows cover can guide impurities such as grinding fluid and debris to slide down quickly along the inclined surface, preventing accumulation on the surface of the bellows cover, reducing the frequency of manual cleaning, and improving the long-term operation stability of the equipment. It solves the problems of protecting the transmission components and recycling the grinding fluid in silicon carbide processing, and has the characteristics of reliability, cleanliness and economy.

[0008] Preferably, on one side of the support seat, there is a second oil-proof bellows cover that shields the third lead screw drive assembly and expands and contracts as the spindle box rises and falls. On the upper side of the moving platform and on both sides of the workbench, there is a third oil-proof bellows cover that shields the second lead screw drive assembly. Similarly, the second and third oil-proof bellows covers can improve the protection of the third and second lead screw drive assemblies.

[0009] Preferably, the grinding fluid filtration tank includes multiple adjacent flow-through chambers. The adjacent flow-through chambers are connected by flow-through holes with gradually decreasing heights. The bottom of the flow-through chamber is provided with an inclined bottom surface, and both ends of the inclined bottom surface are lower than the connected flow-through holes. The top of the flow-through chamber 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. Through the combined design of primary filtration by multiple filter screens, gravity sedimentation in gradient chamber bodies, and impurity collection on the inclined bottom surface, it specifically solves the problem that the grinding fluid in silicon carbide processing is easily contaminated by fine particles, ensures the stability of the cooling and lubrication effects, and ultimately improves the processing accuracy and equipment life.

[0010] Preferably, the joint surface between the metal powder sintered grinding wheel and the thin-walled cylinder is a serrated joint surface. The serrated joint surface significantly improves the connection strength between the grinding wheel and the thin-walled cylinder through increasing the contact area and the mechanical interlocking structure, avoiding radial or axial displacement or even detachment of the grinding wheel during high-speed rotation or under force, and ensuring the processing safety and stability.

[0011] Preferably, a plurality of reinforcing rib plates are arranged around the inner side wall of the thin-walled cylinder in a circumferential direction. The height of the reinforcing rib plates gradually increases from the end close to the metal powder sintered grinding wheel to the other end. The design of the gradually changing rib plate height enables the load to be smoothly transmitted along the axial direction of the thin-walled cylinder, avoiding stress concentration caused by sudden changes in the rib plate height. Especially under the working condition of high-speed rotation, the difference in the axial distribution of the centrifugal force will be effectively balanced by the gradually changing characteristics of the rib plate height, enhancing the structural fatigue life.

[0012] Preferably, both the support seat and the base are internally provided with vertically and horizontally crisscrossing reinforcing ribs, which can increase the stiffness of the entire equipment and reduce vibration during processing.

[0013] Preferably, a sheet metal baffle is arranged along the edge on the upper side of the base, and a double-door is arranged on the side of the sheet metal baffle away from the support seat.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] By providing a special tool for combining the metal powder sintered grinding wheel with the thin-walled cylinder, the processing position can be quickly cooled, improving the processing accuracy. The grinding fluid flowing through the headstock can quickly take away the heat generated during the use of the headstock, reducing the thermal expansion deformation of the headstock and ensuring the processing accuracy of the silicon carbide material. The plate heat exchanger can maintain the low temperature of the grinding fluid entering the headstock, improving the cooling effect; the long-life characteristic of the metal powder sintered grinding wheel reduces the tool change frequency; the large-capacity design and automatic backwashing function of the grinding fluid filter tank reduce the manual fluid change frequency and reduce the waste of consumables; the integrated design of the cooling flow channel and the grinding fluid circulation reduces the external pipeline connection failure points and improves the reliability of the long-term operation of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is the overall three-dimensional structure diagram of the present invention;

[0017] Figure 2 is the three-dimensional structure diagram of the present invention after removing the sheet metal baffle;

[0018] Figure 3 is the main view cross-sectional structure diagram of the present invention after removing the sheet metal baffle;

[0019] Figure 4 is the side view cross-sectional structure diagram of the present invention after removing the sheet metal baffle;

[0020] Figure 5 Schematic cross-sectional view of the local structure of the present invention;

[0021] Figure 6 Front cross-sectional structure diagram of the special milling and grinding tool of the present invention.

[0022] Reference numerals:

[0023] 1. Base, 10. Motor, 11. Third lead screw drive assembly, 12. Moving platform, 13. Special milling and grinding tool, 131. Thin-walled cylinder, 132. Metal powder sintered grinding wheel, 133. Serrated joint surface, 134. Reinforcing rib plate, 135. Grinding fluid injection hole, 137. Tool shank, 14. Tool 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 chamber, 2. Sheet metal baffle, 20. Cooling channel, 21. First lead screw drive assembly, 22. Reinforcing rib, 23. Return pipe, 24. Third oil-proof bellows cover, 3. Double-door, 4. Workbench, 5. Second lead screw drive assembly, 6. Support base, 7. Headstock, 8. Second oil-proof bellows cover, 9. First oil-proof bellows cover. Detailed implementation manners

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0025] As Figure 1-6As shown in the figure, in this embodiment, in order to solve the problem that the existing wire cutting technology and the external cylindrical grinding machine process have relatively large limitations for processing silicon carbide materials, a milling and grinding composite processing device for silicon carbide materials is provided, including a base 1. On the upper side of the base 1, there is a moving platform 12 driven to move left and right by a first lead screw drive assembly 21. On the upper side of the moving platform 12, there is a workbench 4 driven to move back and forth by a second lead screw drive assembly 5. On one side of the base 1, there is a support base 6. On the side of the support base 6 facing the moving platform 12, there is a spindle box 7 driven to lift by a third lead screw drive assembly 11. A tool clamping unit 14 is installed on the spindle box 7. A special milling and grinding tool 13 is clamped at the lower end of the tool clamping unit 14. The special milling and grinding tool 13 includes a thin-walled cylinder 131, a metal powder sintered grinding wheel 132 arranged at the open end of the thin-walled cylinder 131, and a tool shank 137 arranged at the closed end of the thin-walled cylinder 131. A grinding fluid injection hole 135 pointing to the metal powder sintered grinding wheel 132 is arranged on the tool shank 137. A grinding fluid filter box 19 is installed on one side of the base 1. A plate heat exchanger 18 is connected and installed on the upper side of the grinding fluid filter box 19. A grinding fluid storage tank 17 connected to the plate heat exchanger 18 through a pipeline is installed inside the support base 6. A number of interconnected cooling channels 20 are arranged inside the spindle box 7. The grinding fluid storage tank 17 is connected to the inlet of the cooling channel 20 through a hose. The outlet of the cooling channel 20 is connected to the tool clamping unit 14 through a pipeline. By setting a special tool that combines a metal powder sintered grinding wheel and a thin-walled cylinder, the processing position can be quickly cooled, improving the processing accuracy. Using the grinding fluid flowing through the spindle box 7 can quickly take away the heat generated by the spindle box 7 during use, reducing the thermal expansion deformation of the spindle box 7 and ensuring the processing accuracy of silicon carbide materials. The plate heat exchanger 18 can maintain the low temperature of the grinding fluid entering the spindle box 7, improving the cooling effect.

[0026] Specifically, silicon carbide has a high hardness (Mohs hardness 9.2 - 9.3). Traditional grinding wheels (such as resin-bonded diamond grinding wheels) are prone to a decrease in processing efficiency and accuracy deviation due to abrasive grain shedding or binder wear during high-speed milling and grinding. Therefore, in this embodiment, a metal powder sintered grinding wheel 132 is used as the cutting / grinding component. Utilizing the high wear resistance of the metal binder and the strong holding force for abrasive grains (such as diamond micropowder), the service life of the grinding wheel is significantly improved, the frequency of frequent tool changes is reduced, and the processing cost is lowered. Moreover, the metal powder sintered grinding wheel 132 and the thin-walled cylinder 131 are integrally sintered and formed, avoiding the problem of mechanical connection loosening between the traditional grinding wheel and the tool shank, ensuring the structural stability during high-speed rotation, and reducing processing surface defects (such as chatter marks and edge chipping) caused by vibration.

[0027] In addition, during the milling and grinding process, high heat is generated by the friction between the metal powder sintered grinding wheel 132 and the silicon carbide material. The local temperature can reach over 1000°C, which easily leads to thermal failure of the grinding wheel grains (such as diamond carbonization) and thermal damage to the workpiece surface (such as oxide layer, lattice distortion). Therefore, the tool holder 137 is provided with a coolant injection hole 135. The coolant injection hole 135 is obliquely arranged, and the number can be set according to needs, such as arranged in 3 - 4, directly injecting coolant into the contact area between the grinding wheel and the workpiece to achieve fixed-point cooling, quickly taking away the frictional heat, and suppressing high-temperature wear of the grinding wheel and 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 tapered 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 an external hose. When the special milling and grinding tool 13 rotates at high speed, the coolant can also be continuously transported into the coolant injection hole 135.

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

[0030] Moreover, in this embodiment, through the linear motion of the XYZ axes of the moving platform 12, the workbench 4, and the spindle box 7, the composite motion of the milling and grinding tool (such as face milling, contour grinding) is realized, which can perform low-stress cutting for the complex shape of the silicon carbide workpiece (such as wafer edge chamfering, groove machining), avoiding the stress concentration area of traditional single-axis machining.

[0031] In the prior art, the high thermal conductivity of silicon carbide causes the machining heat to be rapidly transferred to the spindle system, leading to thermal expansion and deformation of the spindle (such as axial thermal elongation > 10 μm), which destroys the machining accuracy. At the same time, the high temperature affects the lubrication performance of the grinding fluid. The internal of the spindle box 7 integrates a cooling flow channel 20, and the heat generated by the spindle box and the main heat-generating components is taken away by the circulation of low-temperature grinding fluid (such as 20 ± 1 °C), controlling the spindle temperature rise ≤ 5 °C to ensure the position accuracy during high-speed rotation (such as radial runout ≤ 5 μm). The grinding fluid storage tank 17 is connected in series with the grinding fluid filtration tank 19, and multi-stage filtration is used to remove grinding dust (SiC particles) and metal powder shed from the grinding wheel, avoiding impurities being sprayed onto the machining area with the coolant and causing scratches on the workpiece surface (defect size > 10 μm). After being fully filtered by the grinding fluid filtration tank 19, the grinding fluid is relatively clean and will not block the plate heat exchanger 18 when entering 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. Therefore, the low temperature of the grinding fluid entering the spindle box 7 can be maintained, improving the cooling effect. 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 the power for circulation. Since the grinding fluid storage tank 17 is connected to the cooling flow channel 20 of the spindle box 7 through a hose, the lifting of the spindle box 7 will not affect the grinding fluid in the grinding fluid storage tank 17 from entering the cooling flow channel 20 and will not cause interference.

[0032] In this embodiment, as Figure 3 shown, there are multiple hollow inner cavities inside the spindle box 7, and the cooling flow channel 20 is arranged along the side wall of the hollow inner cavity. The hollow inner cavity can improve the strength of the spindle box 7, and individual hollow inner cavities can also be used to install the tool clamping unit 14, the motor 10 and other components. Arranging the cooling flow channel 20 along the hollow inner cavity can improve the cooling effect on these components. Specifically, the hollow inner cavity can have various structures. While reducing the weight of the spindle box (weight reduction of 15% - 20%), through the design of the reinforcing ribs on the side wall (such as setting support ribs with a thickness of 3 - 5 mm between the hollow cavities), the rigidity of the spindle box is maintained (bending stiffness ≥ 100 N / μm), avoiding machining vibration introduced by structural deformation.

[0033] Meanwhile, to improve the vibration damping effect, a number of rubber damping balls 15 are tightly filled in the hollow inner cavity. The rubber damping balls 15 utilize elastic deformation and internal friction to dissipate vibration energy, especially being effective for the high-frequency vibrations commonly seen in milling and grinding operations. When the spindle box vibrates, the mutual extrusion, friction, and self-deformation among 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. Additionally, by adjusting the density of the rubber damping balls 15 (filling rate 60% - 80%) and the rubber hardness (Shore hardness 40 - 60A), the natural frequency of the spindle box 7 can be increased from 150 Hz of the traditional solid structure to 250 - 300 Hz, avoiding the typical excitation frequencies in milling and grinding operations (such as 200 Hz, corresponding to the 60th harmonic when the grinding wheel speed is 12,000 rpm), and suppressing resonance from the source.

[0034] As an elastic medium, the rubber damping balls 15 form a flexible support in the hollow inner cavity, reducing the rigid vibration transmission between the spindle box and the support seat 6 and the lead screw drive assembly. For example, when the workbench 4 generates periodic vibrations at the 5 - μm level due to lead screw pitch errors, the vibration amplitude transmitted to the spindle after attenuation by the damping balls is ≤1 μm, avoiding the machining surface chatter defects caused by vibrations (the texture depth is reduced from 50 nm of the traditional structure to below 10 nm).

[0035] The isotropic damping effect of the rubber material of the rubber damping balls 15 can simultaneously suppress the vibrations in the X, Y, and Z axes, especially achieving balanced control of the sensitive radial vibration (affecting surface roughness) and axial vibration (affecting machining depth accuracy) in silicon carbide machining, ensuring that the relative displacement in the contact area between the grinding wheel and the workpiece is ≤2 μm.

[0036] In this embodiment, on the upper side of the base 1, first anti-oil bellows covers 9 that block the first lead screw drive assembly 21 are provided on both sides of the moving platform 12. The first anti-oil bellows covers 9 are inclined to one side. At a position on the base 1 that matches the inclination direction of the first anti-oil bellows cover 9, a return pipe 23 extending to the grinding fluid filtration tank 19 is provided. The anti-oil bellows cover is inclined, which can guide impurities such as grinding fluid and debris to quickly slide down along the inclined plane, avoid accumulation on the surface of the bellows cover, reduce the frequency of manual cleaning, and improve the stability of the long-term operation of the equipment. It solves the problems of the protection of transmission components and the recycling of grinding fluid in silicon carbide processing, and has reliability, cleanliness and economy. Specifically, the first lead screw drive assembly 21 is responsible for driving the left and right translation of the moving platform 12 and is a key transmission component of the equipment. During the silicon carbide processing, a large amount of grinding fluid (containing abrasive particles and debris) and oil stains will be generated. If it directly contacts the lead screw, it is easy to cause lead screw wear, lubrication failure, and even jamming, affecting the transmission accuracy and the service life of the equipment. Therefore, the first anti-oil bellows cover 9 can prevent the grinding fluid from contacting the first lead screw drive assembly 21; in addition, the first anti-oil bellows cover 9 is inclined, which can guide impurities such as grinding fluid and debris to quickly slide down along the inclined plane, avoid accumulation on the surface of the bellows cover, reduce the frequency of manual cleaning, and improve the stability of the long-term operation of the equipment. The return pipe 23 on the base matches the inclination direction of the first anti-oil bellows cover 9 and can directly introduce the sliding grinding fluid into the grinding fluid filtration tank 19 to form a "protection-recovery-filtration-circulation" closed-loop system. The inclination angle of the first anti-oil bellows cover 9 is designed to be 30°-45° to drive the grinding fluid to quickly slide down by gravity and avoid liquid accumulation. A diversion lip with a height of 1-2 mm is provided at the bottom edge of the first anti-oil bellows cover 9 to guide the liquid to gather in the direction of the return pipe 23. As a supplementary solution, a layer of 20-50 mesh stainless steel filter screen can be pasted on the inner side of the inclined surface of the first anti-oil bellows cover 9 to intercept silicon carbide debris with a diameter > 0.5 mm and avoid large particle impurities from entering the return pipe and causing blockage. The edge of the filter screen is connected to the bellows cover through Velcro or detachable buckles for easy regular cleaning.

[0037] In addition, on one side of the support base 6, a second anti-oil bellows cover 8 that blocks the third lead screw drive assembly 11 and expands and contracts as the main spindle box 7 rises and falls is provided. On the upper side of the moving platform 12, third anti-oil bellows covers 24 that block the second lead screw drive assembly 5 are provided on both sides of the workbench 4. Similarly, the protection of the third lead screw drive assembly 11 and the second lead screw drive assembly 5 can be improved through the second anti-oil bellows cover 8 and the third anti-oil bellows cover 24. Among them, the first anti-oil bellows cover 9, the second anti-oil bellows cover 8 and the third anti-oil bellows cover 24 can be made of oil-resistant and wear-resistant nitrile rubber or polyurethane fiber composite materials with a thickness of 3-5 mm, which have both flexibility and tear resistance.

[0038] In this embodiment, the grinding fluid filtration tank 19 includes a plurality of adjacent flow-through chambers 193, which are connected by flow-through holes with gradually decreasing heights. 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. Among them, a liquid inlet is provided at the top of the flow-through chamber 193 corresponding to the return pipe 23, and at least one layer of filter screen 191 is provided on the liquid inlet. Through the combined design of primary filtration by multiple filter screens, gravity precipitation in gradient chambers, and impurity collection on the inclined bottom surface, the problem that the grinding fluid is easily contaminated by fine particles during the processing of silicon carbide is specifically solved, ensuring the stability of the cooling and lubrication effects, and ultimately improving the processing accuracy and the service life of the equipment. Specifically, the filter screen 191 can first filter out larger-diameter silicon carbide debris, metal grinding chips, etc., to prevent them from entering the subsequent flow-through chambers and reducing the subsequent precipitation burden; adjacent flow-through chambers 193 are connected by flow-through holes with gradually decreasing heights. When the grinding fluid flows from the high chamber to the low chamber, the flow rate slows down, and particulate impurities are stratified and precipitated due to gravity: that is, larger particles precipitate in the first flow-through chamber first, and fine particles flow into the next-stage chamber with the liquid and continue to precipitate. This gradient filtration can efficiently separate impurities of different particle sizes, especially suitable for sub-micron particles (such as broken SiC powder) generated during the processing of silicon carbide. 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 precipitated impurities naturally gather at the lowest point of the chamber bottom, preventing the impurities from being lifted again when the liquid flows, and at the same time facilitating centralized cleaning (such as discharging through a drain valve). Therefore, silicon carbide has a high hardness (Mohs hardness 9.5), and the debris generated during the processing is sharp and fine. If not effectively filtered, it is easy to block the grinding fluid injection holes 135, the cooling channels 20, or the pores of the grinding wheel, resulting in insufficient cooling and increased tool wear. This structure ensures the cleanliness of the returned grinding fluid through multi-stage filtration and precipitation, maintains the injection pressure and cooling effect, extends the tool life, and improves the processing accuracy.

[0039] As a specific embodiment of the grinding fluid filtration tank 19, the number of flow-through chambers: 3 (can be increased or decreased according to the processing accuracy requirements), the material is stainless steel (corrosion-resistant, suitable for water-based grinding fluid), and the dimensions of the chambers are as follows: The first chamber (liquid inlet chamber): length × width × height = 500 mm × 300 mm × 400 mm, and two layers of filter screens (191) are provided at the top liquid inlet (the first layer is a 200-mesh coarse filter, and the second layer is a 500-mesh fine filter); the second chamber: length × width × height = 500 mm × 300 mm × 350 mm, and is connected to the first chamber through a flow-through hole with a diameter of 50 mm and a height difference of 50 mm; the third chamber (liquid outlet chamber): length × width × height = 500 mm × 300 mm × 300 mm, and is connected to the second chamber through a flow-through hole with a diameter of 40 mm and a height difference of 50 mm. The inclination angle of the inclined bottom surface at the bottom of each chamber is 15°, and both ends are 10 mm lower than the bottom edge of the flow-through hole. A DN25 drain valve is provided at the lowest point, and the drain valve is a ball valve for convenient regular slag discharge.

[0040] In this embodiment, the joint surface between the metal powder sintered grinding wheel 132 and the thin-walled cylinder 131 is a serrated joint surface 133. Silicon carbide material has high hardness (Mohs hardness 9.2 - 9.3) and high brittleness. During milling and grinding, the grinding wheel needs to bear high-frequency impact loads and centrifugal forces. The serrated joint surface 133 significantly improves the connection strength between the grinding wheel and the thin-walled cylinder by increasing the contact area (compared with a flat joint) and the mechanical interlocking structure, avoiding radial or axial displacement or even detachment of the grinding wheel during high-speed rotation or under load, and ensuring the safety and stability of processing. Traditional flat joints are prone to interface cracking due to stress concentration. The serrated structure disperses the load to multiple tooth surfaces through the gradient transition of the tooth shape, reducing the local stress peak and extending the overall tool life. In addition, the tooth peaks and valleys of the serrated joint surface 133 form a locking effect, which 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 interface slippage. From the perspective of process forming, when the metal powder sintered grinding wheel is formed, the serrated grooves can be directly formed by a mold, enabling the grinding wheel material to be embedded in the tooth-shaped structure of the thin-walled cylinder, achieving double fixation of metallurgical bonding and mechanical bonding, and avoiding the complex processes of subsequent gluing or mechanical fastening.

[0041] As an embodiment of the serrated joint surface 133: The serrated joint surface 133 is machined on the top end face of the thin-walled cylinder 131, with a tooth depth of 1.5 - 3 mm, a tooth pitch of 2 - 4 mm, a tooth shape angle of 60° - 90°, the grooves are evenly distributed circumferentially, and the number is 12 - 24 teeth. Before sintering the metal powder sintered grinding wheel 132, the preformed blank is filled into the trapezoidal grooves of the thin-walled cylinder, and through a powder metallurgy sintering process (such as vacuum sintering, temperature 800 - 1200 °C), the grinding wheel material (such as bronze-based, resin-based or diamond powder) forms a composite interface of metallurgical bonding and mechanical embedding with the thin-walled cylinder.

[0042] In this embodiment, a plurality of reinforcing rib plates 134 are arranged around the inner side wall of the thin-walled cylinder 131 in a circumferential manner. The height of the reinforcing rib plates 134 gradually increases from one end close to the metal powder sintered grinding wheel 132 to the other end. Since the wall thickness of the thin-walled cylinder 131 is relatively thin, it is prone to radial or axial deformation during high-speed rotation or under grinding loads. The reinforcing rib plates 134 are evenly distributed along the circumference, which can significantly improve the bending and torsional stiffness of the cylinder wall. The height of the reinforcing rib plates 134 gradually increases from the end close to the grinding wheel to the other end, which conforms to the principle of stress gradient distribution: the load at the end close to the grinding wheel (directly bearing the grinding force) is mainly local contact stress, and a relatively low rib plate height can meet the stiffness requirements; while the other end far from the grinding wheel may bear the cumulative effect of bending moment or centrifugal force, and the overall stiffness is compensated by higher rib plates to prevent the thin-walled cylinder from overall bending or instability. For example: 8 rectangular rib plates are evenly distributed along the circumference, the width of the rib plate is 10 mm, and the thickness is 2 mm; the height of the rib plate at the end close to the grinding wheel h1 = 8 mm, the height of the rib plate at the end far from the grinding wheel h2 = 15 mm, and it changes linearly in the middle (h(x) = 8 + 7x / 200, x is the axial distance, unit mm); the rib plates extend linearly along the axis, the inner surface is integrally formed with the inner wall of the thin-walled cylinder, and the outer surface is avoided from the serrated joint surface 133 area of the metal powder sintered grinding wheel 132 to avoid interference.

[0043] In this embodiment, reinforcing ribs 22 arranged vertically and horizontally are provided inside both the support base 6 and the base 1, which can increase the stiffness of the entire device and reduce vibration during processing.

[0044] A sheet metal baffle 2 is arranged along the edge on the upper side of the base 1, and a double-door 3 is arranged on the side of the sheet metal baffle 2 far from the support base 6.

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

[0046] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0047] In the present invention, unless otherwise clearly specified or limited, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

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 to translate left and right is arranged on the upper side of the base, a workbench driven by a second screw transmission assembly to translate forward and backward is arranged on the upper side of the movable platform, a support seat is arranged on one side of the base, and a spindle box driven by a third screw transmission assembly to lift and lower is arranged on the side of the support seat facing the movable platform, characterized in that: A tool clamping unit is installed on the spindle box, and a special milling tool is clamped at the lower end of the tool clamping unit. The special milling tool comprises a thin-walled tube, a metal powder sintered grinding wheel arranged at the open end of the thin-walled tube, and a tool handle arranged at the closed end of the thin-walled tube. The tool handle is provided with a grinding fluid injection hole pointing to the metal powder sintered grinding wheel. A grinding fluid filter box is installed on one side of the base, and a plate heat exchanger is installed on the upper side of the grinding fluid filter box. A grinding fluid storage box connected to the plate heat exchanger through a pipeline is installed inside the support seat. A plurality of interconnected cooling channels are arranged inside the spindle box. The grinding fluid storage box is connected to the inlet of the cooling channel through a hose, and the outlet of the cooling channel is connected to the tool clamping unit through a pipeline.

2. The milling and grinding composite processing device for silicon carbide material according to claim 1, characterized in that: The spindle box has a plurality of hollow inner cavities inside, and the cooling channels are arranged along the side walls of the hollow inner cavities.

3. The milling and grinding composite processing device for silicon carbide material according to claim 2, characterized in that: The hollow inner cavity is tightly filled with a plurality of rubber damping balls.

4. The milling and grinding composite processing device for silicon carbide material according to claim 1, characterized in that: The upper side of the base is located on both sides of the movable platform and is provided with a first oil-proof accordion cover that shields the first screw transmission assembly. The first oil-proof accordion cover is inclined to one side, and a reflux pipe extending to the grinding fluid filter box is provided at a position on the base that matches the inclination direction of the first oil-proof accordion cover.

5. The milling and grinding composite processing device for silicon carbide material according to claim 4, characterized in that: A second oil-proof accordion cover is arranged on one side of the support seat to shield the third screw transmission assembly and to extend and retract as the spindle box rises and falls. The upper side of the movable platform is located on both sides of the workbench and a third oil-proof accordion cover for the second screw transmission assembly is arranged.

6. The milling and grinding composite processing device for silicon carbide material according to claim 4, characterized in that: The grinding fluid filter box includes a plurality of adjacent circulation bins, which are connected by circulation holes whose heights decrease successively. The bottom of the circulation bin is provided with an inclined bottom surface, and both ends of the inclined bottom surface are lower than the connected circulation holes. The top of the circulation bin corresponding to the reflux pipe is provided with a liquid inlet, and at least one layer of filter screen is provided on the liquid inlet.

7. The milling and grinding composite processing device for silicon carbide material according to any one of claims 1 to 5, characterized in that: The joint surface between the metal powder sintered grinding wheel and the thin-walled tube is a serrated joint surface.

8. The milling and grinding composite processing device for silicon carbide material according to claim 6, characterized in that: A plurality of reinforcing ribs are arranged around the circumference of the inner side wall of the thin-walled tube, and the height of the reinforcing ribs gradually increases from one end close to the metal powder sintering grinding wheel to the other end.

9. The milling and grinding composite processing device for silicon carbide material according to any one of claims 1 to 5, characterized in that: The support seat and the base are both provided with reinforcing ribs staggered horizontally and vertically.

10. The milling and grinding composite processing device for silicon carbide material according to any one of claims 1 to 5, characterized in that: A sheet metal baffle is arranged along the edge of the upper side of the base, and a double door is arranged on the side of the sheet metal baffle away from the support seat.

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