A grinding machine for machining the outer spherical surface structure of a femoral head

Abstract

The present application relates to the technical field of machining, in particular to a grinding machine for processing the outer spherical surface structure of a femoral head, and provides the grinding machine for processing the outer spherical surface structure of the femoral head, which comprises a machine tool body, a polishing mechanism arranged on the machine tool body, the polishing mechanism comprising a grinding wheel, the grinding wheel being provided with a groove, the inner diameter of the groove being smaller than the diameter of a ball head workpiece, an adjusting mechanism arranged on the machine tool body, the adjusting mechanism being provided with a mounting part movable in a horizontal plane, a driving mechanism arranged on the mounting part, and the power output end of the driving mechanism being provided with a clamping tool, the clamping tool being used for clamping the ball head workpiece, wherein the central axis of the clamping tool and the central axis of the groove are located on the same horizontal plane, and the grinding machine for processing the outer spherical surface structure of the femoral head provided by the present application has simple structure and low cost.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and in particular to a grinding machine tool for machining the outer spherical structure of the femoral head. Background Technology

[0002] The femoral head is a core component of artificial hip joint prostheses, and the geometric accuracy and surface quality of its outer spherical surface directly affect the lifespan of the prosthesis and the patient's quality of life. The outer spherical surface of the femoral head requires extremely high sphericity accuracy (typically ≤0.009mm) and surface roughness (Ra≤0.1μm), and requires comprehensive precision machining of the entire spherical surface, including the bottom area.

[0003] Currently, the mechanical equipment used for machining the outer diameter of the femoral head in artificial hip joint implants generally includes components such as a machine tool bed, spindle, power head, clamping fixture, machining tools, and control system. Existing grinding processes for the outer spherical surface of the femoral head mainly employ CNC machine tools for external cylindrical grinding, which is performed by grinding through contact between the grinding wheel and the outer surface of the workpiece.

[0004] However, existing technologies have significant drawbacks: the outer diameter of such products currently machined using CNC machine tools cannot meet the roundness requirements of the product's outer diameter. The required roundness is 0.009mm, but the actual roundness after machining is between 0.01mm and 0.02mm, failing to meet the requirement. Specifically, due to the geometric characteristics of ball-head workpieces, traditional external cylindrical grinding can only effectively machine the sides and upper half of the ball head. Geometric interference exists in the spherical crown area at the bottom of the ball head, preventing the grinding wheel from contacting this area and creating a machining dead angle. This machining dead angle not only prevents the bottom area of ​​the ball head from achieving the same surface quality as other areas, but more importantly, it affects the overall roundness accuracy of the ball head, causing the roundness error after machining to exceed the stringent requirements of medical devices. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a grinding machine tool for machining the outer spherical structure of the femoral head, which has a simple structure and low cost.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, this application provides a grinding machine tool for machining the outer spherical structure of the femoral head, comprising: a machine tool body; a grinding mechanism disposed on the machine tool body, the grinding mechanism including a grinding wheel having a groove, the inner diameter of the groove being smaller than the diameter of the femoral head workpiece; an adjustment mechanism disposed on the machine tool body, the adjustment mechanism having a mounting part movable in a horizontal plane; and a drive mechanism disposed on the mounting part, the power output end of the drive mechanism being provided with a clamping fixture for clamping the femoral head workpiece; wherein, the central axis of the clamping fixture and the central axis of the groove are located on the same horizontal plane.

[0009] In one possible implementation, the groove opening is provided with a slope structure for abutting the ball-shaped workpiece.

[0010] In one possible implementation, the grinding mechanism also includes a drive motor, the power output end of which is provided with a mounting shaft for driving the grinding wheel to rotate.

[0011] In one possible implementation, the grinding wheel includes a plurality of fan-shaped units evenly distributed circumferentially, the plurality of fan-shaped units surrounding a groove; the grinding mechanism also includes an adjustment assembly mounted on a mounting shaft, the adjustment assembly having a plurality of adjustment parts movable radially, the plurality of adjustment parts being connected to the plurality of fan-shaped units respectively, for synchronously adjusting the plurality of fan-shaped units radially.

[0012] In one possible implementation, the groove includes a first grinding groove and a second grinding groove arranged axially, the first grinding groove being adjacent to the clamping fixture, and the inner diameter of the first grinding groove being larger than the inner diameter of the second grinding groove.

[0013] In one possible implementation, the abrasive grain size of the first grinding groove is larger than that of the second grinding groove; or, the abrasive grain size of the first grinding groove is smaller than that of the second grinding groove.

[0014] In one possible implementation, the interior of the groove is provided with an arc-shaped surface, which is opposite to the opening of the groove. The abrasive grain size of the arc-shaped surface is smaller than that of the first and second grinding grooves.

[0015] In one possible implementation, a sliding cavity is provided axially within the mounting shaft. The adjustment assembly includes: an electric telescopic unit disposed within the sliding cavity, with a telescopic block at its output end; a mounting plate connected to the end of the mounting shaft, the mounting plate having multiple strip-shaped holes radially arranged; multiple sliding blocks slidably disposed within the multiple strip-shaped holes, each sliding block being detachably connected to multiple fan-shaped units; and multiple connecting rods, one end of each connecting rod being hinged to a telescopic block, and the other end being hinged to each sliding block.

[0016] In one possible implementation, the adjustment mechanism further includes: a linear feed unit having a movable end that can move along a first direction; an arc-shaped guide rail disposed at the movable end of the linear feed unit; a slider that slides in cooperation with the arc-shaped guide rail; a rack connected to the bottom of the slider; an adjustment motor disposed at the movable end, the output end of the adjustment motor being provided with a gear that meshes with the rack; wherein, the drive mechanism is disposed on the slider.

[0017] In one possible implementation, the center of the arc-shaped guide rail is located at the center of the ball-shaped workpiece.

[0018] (III) Beneficial Effects

[0019] Compared with existing technologies, this invention provides a grinding machine tool for machining the outer spherical structure of the femoral head, which has the following beneficial effects: This grinding machine tool for machining the outer spherical structure of the femoral head uses a grinding wheel with grooves, wherein the inner diameter of the grooves is smaller than the diameter of the ball head workpiece. This prevents the ball head workpiece from being completely inserted into the groove, but instead overlaps the edge of the groove opening. When the grinding wheel rotates, the edge of the groove grinds the outer surface of the ball head workpiece, effectively solving the problem of insufficient roundness accuracy caused by the machining dead angle at the bottom of the ball head in traditional CNC machine tool external cylindrical grinding. When the ball head workpiece is placed above the groove, due to size limitations, the ball head can only overlap the edge of the groove, forming a ring contact. As the grinding wheel rotates, the edge of the groove acts as a continuous ring grinding edge, grinding the surface of the ball head in contact with it. Simultaneously, through precise adjustment of the mounting part of the adjustment mechanism in the horizontal plane, in conjunction with the drive mechanism, the ball head workpiece is rotated and its position changed. This ensures that different areas of the ball head, including the bottom crown area that is inaccessible by traditional processes, can establish effective contact with the groove edge, achieving full-coverage grinding of the outer surface of the ball head. The alignment of the clamping fixture's central axis with the groove's central axis on the same horizontal plane ensures precise alignment and a stable geometric relationship between the ball head workpiece and the grinding wheel groove, eliminating the adverse effects of unprocessed areas caused by bottom dead angles on overall roundness in traditional cylindrical grinding. Through this uniform grinding method across the entire surface, the amount of material removed and the surface quality of each part of the ball head are uniformly controlled, thereby effectively improving the roundness of the ball head workpiece. Attached Figure Description

[0020] Figure 1 This illustration shows a planar structural diagram of a grinding machine tool for machining the outer spherical structure of the femoral head, according to an embodiment of this application.

[0021] Figure 2 This is a top view schematic diagram of a grinding machine tool for machining the outer spherical structure of the femoral head, provided in an embodiment of this application.

[0022] Figure 3 This diagram shows a cross-sectional view of a grinding wheel along its axial direction, as provided in an embodiment of this application.

[0023] Figure 4 This diagram shows a radial cross-sectional structure of a grinding wheel provided in an embodiment of this application.

[0024] Figure 5 This diagram shows a cross-sectional view of an installation shaft and adjustment assembly provided in an embodiment of this application.

[0025] Figure 6 This diagram shows a top view of an arc-shaped guide rail, slider, and rack provided in an embodiment of this application.

[0026] Figure 7 This diagram shows a top view of a rack and pinion transmission according to an embodiment of this application.

[0027] Marked in the attached diagram:

[0028] a. Ball-shaped workpiece;

[0029] 1. Machine tool body;

[0030] 2. Grinding mechanism; 21. Grinding wheel; 211. Groove; 2111. Sloping structure; 2112. First grinding groove; 2113. Second grinding groove; 2114. Arc-shaped surface; 212. Fan-shaped unit; 22. Drive motor; 23. Mounting shaft; 231. Sliding cavity; 24. Adjustment assembly; 241. Electric telescopic unit; 242. Telescopic block; 243. Mounting plate; 244. Sliding block; 245. Connecting rod;

[0031] 3. Adjustment mechanism; 31. Linear feed unit; 32. Arc guide rail; 33. Slider; 34. Rack; 35. Adjustment motor; 36. Gear;

[0032] 4. Drive mechanism; 41. Clamping fixture. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see Figures 1 to 7 This application provides a grinding machine tool for machining the outer spherical structure of the femoral head, including a machine tool body 1, a grinding mechanism 2, an adjustment mechanism 3, and a drive mechanism 4, wherein:

[0035] The grinding mechanism 2 is mounted on the machine tool body 1. The grinding mechanism 2 includes a grinding wheel 21, which has a groove 211. The inner diameter of the groove 211 is smaller than the diameter of the ball-head workpiece a.

[0036] The adjustment mechanism 3 is mounted on the machine tool body 1, and the adjustment mechanism 3 has a mounting part that can move in the horizontal plane.

[0037] The drive mechanism 4 is located in the mounting part, and the power output end of the drive mechanism 4 is provided with a clamping fixture 41, which is used to clamp the ball head workpiece a; wherein, the central axis of the clamping fixture 41 and the central axis of the groove 211 are located on the same horizontal plane.

[0038] In this invention, by setting a grinding wheel 21 with a groove 211, wherein the inner diameter of the groove 211 is smaller than the diameter of the ball-shaped workpiece a, the ball-shaped workpiece a cannot be completely inserted into the groove 211, but instead overlaps the edge of the groove 211. When the grinding wheel 21 rotates, the edge of the groove grinds the outer surface of the ball-shaped workpiece a, effectively solving the problem of insufficient roundness accuracy caused by the dead angle at the bottom of the ball head in the external cylindrical grinding of traditional CNC machine tools. When the ball-shaped workpiece a is placed above the groove 211, due to size limitations, the ball head can only overlap the edge of the groove, forming an annular contact. As the grinding wheel 21 rotates, the edge of the groove acts as a continuous annular grinding edge, grinding the surface of the ball head in contact with it. At the same time, by precisely adjusting the mounting part of the adjusting mechanism 3 in the horizontal plane, and cooperating with the driving mechanism 4 to drive the ball-shaped workpiece a to rotate and change position, different areas of the ball head, including the bottom crown area that cannot be reached by traditional processes, can establish effective contact with the edge of the groove, achieving full coverage grinding of the outer surface of the ball head. The alignment of the central axis of the clamping fixture 41 with the central axis of the groove 211 on the same horizontal plane ensures precise alignment and a stable geometric relationship between the ball-shaped workpiece a and the groove 211 of the grinding wheel 21. This eliminates the adverse effects of unprocessed areas caused by bottom dead angles on the overall roundness in traditional cylindrical grinding. Through this uniform grinding method across the entire surface, the amount of material removed and the surface quality of each part of the ball head are uniformly controlled, thereby effectively improving the roundness of the ball-shaped workpiece a.

[0039] Specifically, the inner diameter of the groove 211 is 0.5-3mm smaller than the diameter of the ball-head workpiece a. This dimensional difference ensures that the ball-head workpiece a can stably overlap the edge of the groove. The grinding wheel 21 rotates at a speed of 1000-3000 rpm, forming a continuous grinding edge at the edge of the groove. The mounting part of the adjusting mechanism 3 can be finely adjusted in the X and Y directions in the horizontal plane, with an adjustment accuracy of up to 0.01mm, ensuring precise alignment between the ball-head workpiece a and the central axis of the groove 211. The drive mechanism 4 drives the clamping fixture 41 and the ball-head workpiece a to rotate and adjust their position, realizing relative movement during the grinding process.

[0040] In some embodiments, the groove 211 is provided with a slope structure 2111 for abutting the ball-head workpiece a at the groove opening.

[0041] In this invention, the groove 211 has a slope structure 2111 at the opening for contacting the ball-shaped workpiece a. Grinding is performed through the contact between the slope structure 2111 and the ball-shaped workpiece a. Compared with simple groove edge line contact, the slope structure 2111 provides a larger contact area, thereby increasing the effective grinding area and improving grinding efficiency and surface quality uniformity.

[0042] Specifically, the slope structure 2111 is set with an inclination angle of 15°-45° and a slope width of 2-8mm, forming a ring-shaped grinding contact zone. The slope structure 2111 is configured with the same or slightly finer abrasive grit size as the groove edge to ensure consistent grinding results. When the ball-head workpiece a contacts the slope structure 2111, the contact area increases by 3-5 times compared to simple line contact, the grinding pressure is dispersed, and the grinding force per unit area is more uniform. The geometry of the slope matches the curvature of the ball-head surface to ensure good fit.

[0043] In this embodiment of the invention, the slope structure 2111 is used to achieve the transformation from line contact to surface contact, which not only increases the effective grinding area and improves grinding efficiency, but also improves the distribution of grinding pressure, avoids local overheating, and improves the uniformity and consistency of surface quality.

[0044] In some embodiments, the grinding mechanism 2 further includes a drive motor 22, and the power output end of the drive motor 22 is provided with a mounting shaft 23 for driving the grinding wheel 21 to rotate.

[0045] In this invention, the grinding mechanism 2 includes a drive motor 22. The power output end of the drive motor 22 is provided with a mounting shaft 23 for driving the grinding wheel 21 to rotate. The drive motor 22 provides stable rotational power to the grinding wheel 21, ensuring that the groove edge can grind the ball head workpiece a at a constant linear speed, thereby ensuring the stability and consistency of the grinding quality.

[0046] Specifically, the drive motor 22 is an AC servo motor with a power of 1-5kW and a speed control accuracy of ±0.1%. The mounting shaft 23 is supported by high-precision bearings, with radial runout controlled within 0.002mm. The drive motor 22 achieves stepless speed regulation through a frequency converter, allowing adjustment of the grinding wheel 21 speed according to different grinding stages. The motor and the mounting shaft 23 are connected by a flexible coupling, which can both transmit torque and absorb vibration.

[0047] In some embodiments, the grinding wheel 21 includes a plurality of fan-shaped units 212 evenly distributed along the circumference, the plurality of fan-shaped units 212 forming a groove 211; the grinding mechanism 2 also includes an adjustment assembly 24, the adjustment assembly 24 being mounted on the mounting shaft 23, the adjustment assembly 24 having a plurality of adjustment parts that are movable radially, the plurality of adjustment parts being connected to the plurality of fan-shaped units 212 respectively, for synchronously adjusting the plurality of fan-shaped units 212 radially.

[0048] In this invention, the grinding wheel 21 includes a plurality of fan-shaped units 212 evenly distributed along the circumference. The plurality of fan-shaped units 212 surround a groove 211. By adjusting the position of the plurality of fan-shaped units 212 synchronously along the radial direction through the multiple adjustment parts of the adjustment assembly 24, the effective inner diameter and shape of the groove 211 can be changed, thereby realizing the switching of different grinding stages and completing the entire process from rough grinding to fine grinding in one clamping.

[0049] Specifically, the number of sector-shaped elements 212 is typically 4-8, with each sector-shaped element 212 having an angle of 45°-90°. The adjustment assembly 24, mounted on the mounting shaft 23, has multiple radially movable adjustment parts with an adjustment stroke of ±2-5mm and an adjustment accuracy of up to 0.01mm. Multiple adjustment parts are synchronously adjusted via a mechanical linkage mechanism to ensure the consistency of the position of each sector-shaped element 212. Each sector-shaped element 212 can be independently configured with abrasives of different grit sizes, and the appropriate abrasive is selected for contact by adjusting its radial position.

[0050] In related technologies, grinding with different precision requirements usually requires changing different grinding wheels 21 or re-clamping the workpiece, resulting in long process changeover times, low production efficiency, and the potential for positioning errors from repeated clamping. However, in this embodiment of the invention, the radial adjustment of the fan-shaped unit 212 integrates multiple grinding processes, allowing the entire machining process to be completed in a single clamping. This eliminates positioning errors from repeated clamping, significantly improving production efficiency and machining accuracy, and providing an ideal solution for mass production.

[0051] In some embodiments, the groove 211 includes a first grinding groove 2112 and a second grinding groove 2113 arranged along the axial direction. The first grinding groove 2112 is adjacent to the clamping fixture 41, and the inner diameter of the first grinding groove 2112 is larger than the inner diameter of the second grinding groove 2113.

[0052] In this invention, the groove 211 includes a first grinding groove 2112 and a second grinding groove 2113 arranged along the axial direction. The first grinding groove 2112 is adjacent to the clamping fixture 41 and its inner diameter is larger than that of the second grinding groove 2113. Through the stepped inner diameter design, combined with the radial adjustment of the fan-shaped single unit 212, the ball-head workpiece a can contact the groove area with different inner diameters in sequence, realizing the progressive grinding in stages and avoiding the workpiece deformation and surface quality problems caused by the removal of a large amount of material at one time.

[0053] Specifically, the inner diameter of the first grinding groove 2112 is typically 1-2 mm smaller than the diameter of the ball head, and the inner diameter of the second grinding groove 2113 is 3-5 mm smaller than the diameter of the ball head. The axial length of the first grinding groove 2112 is 5-10 mm, and the axial length of the second grinding groove 2113 is 8-15 mm. When the fan-shaped unit 212 is in a contracted state, the ball head mainly contacts the first grinding groove 2112; when the fan-shaped unit 212 is unfolded, the ball head gradually contacts the second grinding groove 2113. The transition area of ​​the stepped structure is designed with a rounded transition to avoid stress concentration caused by sharp corners.

[0054] In related technologies, ball head grinding typically employs a single grinding depth, which is either inefficient or prone to causing workpiece deformation, making it difficult to find a balance between efficiency and quality. However, in this embodiment of the invention, a stepped groove 211 structure achieves gradient control of the grinding depth, ensuring both high efficiency in the rough grinding stage and high quality in the fine grinding stage, effectively preventing workpiece deformation.

[0055] In some embodiments, the abrasive grain size of the first grinding groove 2112 is larger than that of the second grinding groove 2113; or, the abrasive grain size of the first grinding groove 2112 is smaller than that of the second grinding groove 2113.

[0056] In this invention, the abrasive grain size of the first grinding groove 2112 is larger than that of the second grinding groove 2113, or the abrasive grain size of the first grinding groove 2112 is smaller than that of the second grinding groove 2113. By configuring abrasive grains of different sizes at different axial positions, and in conjunction with the stepped groove structure 211 and the radial adjustment of the fan-shaped unit 212, the optimized configuration of abrasive grain size from coarse grinding to fine grinding or special process requirements is achieved, providing a flexible solution for different processing needs.

[0057] Specifically, when the abrasive grit size of the first grinding groove 2112 is larger than that of the second grinding groove 2113, the first grinding groove 2112 typically uses 60-120 mesh coarse abrasive, and the second grinding groove 2113 uses 240-600 mesh fine abrasive, realizing the traditional grinding process of coarse first and then fine. When the abrasive grit size of the first grinding groove 2112 is smaller than that of the second grinding groove 2113, the first grinding groove 2112 uses 400-800 mesh fine abrasive, and the second grinding groove 2113 uses 80-180 mesh coarse abrasive, suitable for special processes that require precise shaping before removing a large amount of excess material. The binder and hardness of the abrasive can also be matched according to specific requirements.

[0058] In one specific embodiment, the machining of the femoral head uses a first grinding groove of 2112-120 grit abrasive and a second grinding groove of 2113-400 grit abrasive. During the rough grinding stage, the 120 grit abrasive can quickly remove 0.2-0.5 mm of machining allowance, achieving a material removal rate of 15 mm. 3 / min; In the fine grinding stage, 400-mesh abrasive is used to finely process the surface, improving the surface roughness from Ra1.6μm to Ra0.2μm, which meets the surface quality requirements of medical devices.

[0059] In related technologies, grinding with different grit sizes usually requires changing the grinding wheel 21, which is complex, time-consuming, and prone to introducing positioning errors during the grinding wheel 21 replacement process. However, in this embodiment of the invention, by configuring abrasives of different grit sizes in different areas of the same grinding wheel 21 and combining it with a fan-shaped adjustment mechanism, online switching of abrasive grit size is achieved, eliminating the operation time and positioning errors of grinding wheel 21 replacement, and improving production efficiency and consistency of machining accuracy.

[0060] In some embodiments, the interior of the groove 211 is provided with an arc-shaped surface 2114, which is opposite to the opening of the groove 211. The abrasive grain size of the arc-shaped surface 2114 is smaller than that of the first grinding groove 2112 and the second grinding groove 2113.

[0061] In this invention, an arc-shaped surface 2114 is provided inside the groove 211. The arc-shaped surface 2114 is opposite to the groove opening of the groove 211. The abrasive grain size of the arc-shaped surface 2114 is smaller than that of the first grinding groove 2112 and the second grinding groove 2113. When the ball-shaped workpiece a is deeply inserted into the groove 211, it can contact the arc-shaped surface 2114 for final polishing. Thus, on the basis of completing the groove grinding, the surface quality of the ball-shaped workpiece a is further improved, and a mirror polishing effect is achieved.

[0062] Specifically, the radius of curvature of the arc-shaped surface 2114 is 0.5-2 mm larger than the radius of the ball head, ensuring good contact geometry. The arc-shaped surface 2114 is equipped with 800-1500 grit ultrafine abrasive, and the binder is relatively soft, which is beneficial to achieving a polishing effect. The axial length of the arc-shaped surface 2114 is 3-8 mm, located at the innermost end of the groove 211. When the fan-shaped unit 212 is fully extended, the ball head can contact the arc-shaped surface 2114, and polishing is performed under extremely low grinding pressure.

[0063] In one specific embodiment, for the polishing of the femoral head, the curved surface 2114 is equipped with 1200-mesh alumina abrasive, with a radius of curvature of 15mm (the head radius is 14mm). During the polishing stage, the head makes light contact with the curved surface 2114 at a rotation speed of 10rpm, the grinding pressure is controlled below 0.5N, and the polishing time is 1 minute. The final surface roughness reaches Ra0.05μm, which is close to a mirror finish and meets the surface quality requirements of high-end medical devices.

[0064] In related technologies, polishing of ball heads typically requires specialized polishing equipment and processes, increasing production costs and process complexity, and making it difficult to guarantee consistent polishing quality. However, in this embodiment of the invention, by integrating an arc-shaped polishing surface inside the groove 211, polishing is achieved simultaneously with grinding, simplifying the process, reducing equipment investment, and ensuring stable polishing quality.

[0065] In some embodiments, a sliding cavity 231 is provided axially inside the mounting shaft 23, and the adjusting assembly 24 includes: an electric telescopic unit 241 disposed in the sliding cavity 231, with a telescopic block 242 provided at the output end of the electric telescopic unit 241; a mounting plate 243 connected to the end of the mounting shaft 23, with a plurality of strip holes provided radially; a plurality of sliding blocks 244 slidably disposed in the plurality of strip holes, with the plurality of sliding blocks 244 detachably connected to a plurality of fan-shaped units 212; and a plurality of connecting rods 245, one end of which is hinged to the telescopic block 242, and the other end of which is hinged to the plurality of sliding blocks 244.

[0066] In this invention, a sliding cavity 231 is provided axially inside the mounting shaft 23. The adjustment assembly 24 includes a precision mechanical structure comprising an electric telescopic unit 241, a mounting plate 243, multiple sliding blocks 244, and multiple connecting rods 245. The axial movement of the telescopic block 242 is driven by the electric telescopic unit 241, and then converted into the radial movement of the sliding block 244 by the connecting rod 245 mechanism. This controls the radial position of the fan-shaped single unit 212, realizing precise electric adjustment of the effective inner diameter of the fan-shaped grinding wheel 21, and greatly improving the adjustment accuracy and automation level.

[0067] Specifically, the electric telescopic unit 241 employs a precision lead screw mechanism driven by a servo motor, with a stroke of 20-50mm and a positioning accuracy of ±0.005mm. The mounting plate 243 has multiple radially arranged slotted holes, each 15-30mm long and 0.1-0.2mm wider than the sliding block 244, ensuring smooth movement of the sliding block 244. The connecting rod 245 uses a spherical hinge, eliminating jamming during movement. The response time of the entire adjustment process is less than 2 seconds, and the repeatability positioning accuracy reaches ±0.002mm. The output end of the servo motor is connected to a threaded tube, which is threadedly engaged with a threaded rod. The end of the threaded rod furthest from the threaded tube is connected to the sliding block 244. The servo motor drives the threaded tube to rotate, and through the engagement of the threaded tube and the threaded rod, the sliding block 244 slides along the sliding cavity 231. A slotted hole is formed axially on the side wall of the mounting shaft, through which the connecting rod 245 is hinged to the sliding block 244. The servo motor is powered through a slip ring on the mounting shaft 23, which enables effective power supply during rotation.

[0068] Of course, the electric telescopic unit 241 in this application can also adopt other linear drive forms, which will not be elaborated here.

[0069] In related technologies, the adjustment of the grinding wheel 21 is usually done manually, which results in low adjustment accuracy, complex operation, difficulty in achieving automated production, and the introduction of human error during the adjustment process. In this embodiment of the invention, a high-precision automatic adjustment of the sector grinding wheel 21 is achieved through a precision electric adjustment mechanism 3. This not only improves the adjustment accuracy and repeatability but also provides conditions for the integration of automated production lines, thereby improving production efficiency and product quality consistency.

[0070] In some embodiments, the adjustment mechanism 3 further includes: a linear feed unit 31 having a movable end that can move along a first direction; an arc-shaped guide rail 32 disposed at the movable end of the linear feed unit 31; a slider 33 that slides in cooperation with the arc-shaped guide rail 32; a rack 34 connected to the bottom of the slider 33; an adjustment motor 35 disposed at the movable end, the output end of the adjustment motor 35 being provided with a gear 36 that meshes with the rack 34; wherein, the drive mechanism 4 is disposed on the slider 33.

[0071] In this invention, the adjustment mechanism 3 includes a comprehensive motion system comprising a linear feed unit 31, an arc-shaped guide rail 32, a slider 33, a rack 34, and an adjustment motor 35. The linear feed unit 31 enables the linear feed motion of the ball-head workpiece a, while the arc-shaped guide rail 32 and the slider 33 enable the arc-shaped oscillation of the ball-head workpiece a. With the precise angle control of the adjustment motor 35 and the gears 36 and rack 34, the ball-head workpiece a can move along a composite trajectory, ensuring that every area of ​​the ball-head surface can fully contact the groove of the grinding wheel 21, thus achieving true full-surface grinding.

[0072] Specifically, the linear feed unit 31 uses a ball screw drive, with a feed accuracy of ±0.005mm and an adjustable feed speed range of 0.1-10mm / min. The radius of the arc-shaped guide rail 32 is designed according to the ball head size, typically 1.5-3 times the ball head diameter, and the guide rail accuracy grade is P5. The slider 33 and the guide rail adopt a rolling guide pair, resulting in low motion resistance and high precision. The adjusting motor 35 is a stepper motor or servo motor, with an angular resolution of up to 0.01°, and achieves precise angular positioning of the slider 33 through gear 36 and rack 34 transmission.

[0073] In related technologies, full-surface grinding of ball heads typically requires complex five-axis linkage equipment, which is expensive, complex to program, difficult to maintain, and demands high operator skills. However, in this embodiment of the invention, a combination of linear feed and arc oscillation achieves the machining effect of five-axis linkage using a relatively simple two-axis linkage method, reducing equipment costs by approximately 70%, greatly simplifying operation and maintenance, while ensuring machining quality.

[0074] In some embodiments, the center of the arc-shaped guide rail 32 is located at the center of the ball-shaped workpiece a.

[0075] In this invention, the center of the arc-shaped guide rail 32 is located at the center of the ball-shaped workpiece a. Through precise geometric design, it is ensured that the ball-shaped workpiece a maintains a constant contact with the groove of the grinding wheel 21 during the arc swing process, and the grinding depth remains consistent throughout the swing range, thereby ensuring the uniformity and consistency of the processing quality of each part of the ball-shaped surface.

[0076] Specifically, the alignment accuracy between the center of the arc-shaped guide rail 32 and the center of the ball head is controlled within ±0.02mm, achieved through a precision positioning device and adjustment mechanism 3. When the ball head swings along the arc-shaped guide rail 32, the distance from the ball center to the edge of the groove remains constant, ensuring consistent grinding clearance. The guide rail requires high machining accuracy, with the arcuate error controlled within 0.01mm and the surface roughness Ra≤0.8μm.

[0077] In related technologies, the oscillating machining of ball-end workpiece a often fails to ensure consistent grinding depth across different parts, easily leading to localized over-grinding or under-grinding, which affects the geometric accuracy and surface quality of the product. However, in this embodiment of the invention, through precise geometric design coinciding with the center of the arc and the center of the ball, uniform grinding depth is achieved, eliminating the uneven grinding problem in traditional processes and improving the geometric accuracy and surface quality consistency of the ball-end product.

[0078] It should be noted that the terms "one embodiment," "embodiment," "exemplary embodiment," "some embodiments," etc., mentioned in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0079] It should be readily understood that the terms “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on top of something” but also “on top of something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0080] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0081] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0082] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A grinding machine tool for machining the outer spherical structure of the femoral head, characterized in that, include: Machine tool body (1); A grinding mechanism (2) is provided on the machine tool body (1). The grinding mechanism (2) includes a grinding wheel (21) with a groove (211) and the inner diameter of the groove (211) is smaller than the diameter of the ball-head workpiece. An adjustment mechanism (3) is provided on the machine tool body (1), and the adjustment mechanism (3) has a mounting part that can move in the horizontal plane; A drive mechanism (4) is provided at the mounting part. The power output end of the drive mechanism (4) is provided with a clamping fixture (41), which is used to clamp the ball head workpiece. The central axis of the clamping fixture (41) and the central axis of the groove (211) are located on the same horizontal plane; The grinding mechanism (2) further includes a drive motor (22), the power output end of which is provided with a mounting shaft (23) for driving the grinding wheel (21) to rotate; the grinding wheel (21) includes a plurality of fan-shaped units (212) evenly distributed in the circumferential direction, the plurality of fan-shaped units (212) surrounding the groove (211); the grinding mechanism (2) further includes an adjustment component (24), the adjustment component (24) is mounted on the mounting shaft (23), the adjustment component (24) has a plurality of adjustment parts that can move radially, the plurality of adjustment parts are respectively connected to the plurality of fan-shaped units (212), and are used to synchronously adjust the plurality of fan-shaped units (212) radially. The mounting shaft (23) has a sliding cavity (231) arranged axially inside. The adjustment assembly (24) includes: an electric telescopic unit (241) disposed in the sliding cavity (231), and a telescopic block (242) disposed at the output end of the electric telescopic unit (241); a mounting plate (243) connected to the end of the mounting shaft (23), and a plurality of strip holes arranged radially on the mounting plate (243); a plurality of sliding blocks (244) slidably disposed in the plurality of strip holes, and the plurality of sliding blocks (244) detachably connected to the plurality of fan-shaped units (212); and a plurality of connecting rods (245), one end of the plurality of connecting rods (245) being hinged to the telescopic block (242) and the other end being hinged to the plurality of sliding blocks (244).

2. The grinding machine tool for machining the outer spherical structure of the femoral head according to claim 1, characterized in that, The groove (211) is provided with a slope structure (2111) for abutting the ball-head workpiece.

3. The grinding machine tool for machining the outer spherical structure of the femoral head according to claim 1, characterized in that, The groove (211) includes a first grinding groove (2112) and a second grinding groove (2113) arranged along the axial direction. The first grinding groove (2112) is adjacent to the clamping fixture (41), and the inner diameter of the first grinding groove (2112) is larger than the inner diameter of the second grinding groove (2113).

4. The grinding machine tool for machining the outer spherical structure of the femoral head according to claim 3, characterized in that, The abrasive particle size of the first grinding groove (2112) is larger than that of the abrasive particle size of the second grinding groove (2113); Alternatively, the abrasive particle size of the first grinding groove (2112) is smaller than that of the abrasive particle size of the second grinding groove (2113).

5. The grinding machine tool for machining the outer spherical structure of the femoral head according to claim 4, characterized in that, The groove (211) has an arc-shaped surface (2114) inside, which is opposite to the opening of the groove (211). The abrasive grain size of the arc-shaped surface (2114) is smaller than that of the first grinding groove (2112) and the second grinding groove (2113).

6. The grinding machine tool for machining the outer spherical structure of the femoral head according to claim 1, characterized in that, The adjustment mechanism (3) further includes: The linear feed unit (31) has a movable end that can move along a first direction; An arc-shaped guide rail (32) is provided at the moving end of the linear feed unit (31); The slider (33) slides in conjunction with the arc-shaped guide rail (32); A rack (34) is connected to the bottom of the slider (33); An adjusting motor (35) is provided at the moving end, and a gear (36) is provided at the output end of the adjusting motor (35), which meshes with the rack (34); The driving mechanism (4) is disposed on the slider (33).

7. The grinding machine tool for machining the outer spherical structure of the femoral head according to claim 6, characterized in that, The center of the arc-shaped guide rail (32) is located at the center of the ball of the ball-shaped workpiece.

Images