Processing system and processing technology for mobile phone middle frame grinding

Abstract

The invention discloses a processing system and processing technology for mobile phone middle frame grinding, the processing system comprises a stacking and polishing device, a jig, a rolling grinding device and a post-processing device, the stacking and polishing device is used for pre-polishing a mobile phone middle frame sample blank, and the jig is used for loading a plurality of mobile phone middle frames through a limiting space defined by a first limiting plate, a second limiting plate and a positioning rod; the interval hanging tool is used for separating adjacent mobile phone middle frames, the rolling grinding device comprises a shell, a main shaft and a grinding assembly, and the first driving part and the second driving part are installed at the two ends of the main shaft correspondingly so as to drive the roller parts to rotate while the roller parts are driven to move around the main shaft in the circumferential direction to form relative rolling so as to grind the mobile phone middle frames. And the post-treatment device is used for cleaning, blowing and drying the ground middle frame. The process is based on the system, after pre-grinding, the jig is loaded into the roller part, the grinding medium is added, the driving part is started for grinding, the qualified middle frame is obtained through aftertreatment, the grinding efficiency and the yield are improved, and the system is suitable for batch production.

Description

Technical Field

[0001] This invention relates to the field of mobile phone mid-frame processing technology, specifically to a processing system and process for grinding mobile phone mid-frames. Background Technology

[0002] In the manufacturing process of smartphone mid-frames, grinding needs to be connected with CNC milling and subsequent sandblasting and anodizing processes. The current grinding process is as follows: First, the CNC-formed mid-frame blank is pre-treated. Then, the process path is selected according to the precision requirements. If a single-drive revolution process is used, the mid-frame is directly loaded into the fixture and placed into the grinding device roller. After adding the grinding media, the roller is driven to revolve around the main shaft by a single power source. The inertial friction between the media and the mid-frame is used to complete the one-time grinding. If a segmented composite process is used, the blank is first sent to the rough grinding device to remove milling marks and large burrs. Then it is transferred to the fine grinding device to refine the surface. In some cases, an additional grinding is required. Finally, the blank is cleaned and dried.

[0003] However, the existing grinding processes and corresponding equipment have revealed many intractable technical problems in actual mass production: First, the grinding uniformity is poor, resulting in low batch yield. Single-drive rotary grinding devices rely solely on the rotation of the roller to drive the media movement. The grinding media tends to flow along a fixed trajectory, leading to grinding dead zones on the surface of the mid-frame (especially around corners and holes), and the roughness of some areas cannot meet the standards. Although segmented processes can improve accuracy through multiple steps, the parameters of the roughing and fine grinding devices are difficult to match precisely, and the mid-frame is prone to repeated grinding or missed grinding due to positioning deviations during the transfer process. The batch processing yield is usually only 88%-92%, which is difficult to meet the quality requirements of high-end mobile phone mid-frames. Second, the processing efficiency and mass production adaptability are insufficient. To compensate for the uneven grinding problem, the single-drive rotary device requires 50-70 minutes for a single grinding cycle, and the existing fixtures are mostly single-layer or low-cavity designs, resulting in low production capacity per unit time, which cannot adapt to the needs of large-scale mass production. Third, the stability of the roller movement and the grinding effect are limited. The dual-drive structure of existing grinding devices mostly adopts the design of equal tooth ratio, which cannot achieve the composite motion of the roller's revolution and rotation through differentiated transmission. It can only rely on a single motion mode, and the intensity of media disturbance is insufficient. Moreover, the rollers mostly adopt a hexagonal design, and the inner wall motion trajectory is single, which further aggravates the problem of uneven grinding.

[0004] In summary, existing technologies struggle to balance the uniformity, efficiency, and mass production requirements of mobile phone mid-frame grinding. Developing a processing system and technology for mobile phone mid-frame grinding that enables composite motion grinding and improves batch yield and efficiency is a pressing issue that needs to be addressed. Summary of the Invention

[0005] To address the technical problems existing in the prior art, the first objective of this invention is to provide a processing system for grinding the mid-frame of mobile phones. This system achieves a composite motion of the revolution and rotation of the roller by using a differentiated tooth ratio of dual drive units, combined with an octagonal grinding space and a multi-cavity fixture, thereby solving the problems of uneven grinding, low efficiency, and poor motion stability.

[0006] The second objective of this invention is to provide a processing technology for grinding mobile phone mid-frames, which integrates pre-grinding, composite grinding, and post-processing based on the above system, precisely controls grinding parameters, ensures batch processing yield and efficiency, and adapts to the mass production needs of high-end mobile phone mid-frames.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A processing system for grinding the mid-frame of a mobile phone, comprising: A stacking and polishing device used for pre-polishing mobile phone mid-frame blanks; A fixture for mounting multiple mobile phone frames to be ground; A rolling grinding device, located downstream of the stacking polishing device, comprises: The housing has an openable and closable cover on its side wall; A main shaft horizontally positioned within the housing; The grinding assembly disposed within the housing includes a first driving part, a second driving part, and a plurality of roller parts. The first driving part and the second driving part are respectively mounted at both ends of the main shaft. The roller parts are rotatably disposed between the first driving part and the second driving part and are distributed at intervals along the circumference of the main shaft to accommodate the fixture and the grinding media. The second drive unit has a second transmission assembly, which has a first synchronous wheel. The roller part is provided with a second synchronous wheel at one end near the second transmission assembly. The first synchronous wheel and the second synchronous wheel are connected to each other and have different numbers of teeth. The first drive unit drives the roller part to move circumferentially around the main shaft. The second drive unit drives the roller part to rotate by the difference in the number of teeth of the synchronous wheels, so that multiple roller parts form a relative rolling state to grind the mobile phone frame in the fixture. A post-processing device, located downstream of the rolling grinding device, is used to receive the ground mobile phone frame and clean and dry its surface.

[0008] According to one example, a primary grinding device is also included, located downstream of the stacking polishing device and upstream of the rolling polishing device, wherein the primary grinding device performs environmentally friendly grinding on the pre-polished mobile phone frame from upstream to polish the inner edge of the mobile phone frame.

[0009] According to one example, the fixture includes a first limiting plate and a second limiting plate that are parallel to each other, and a plurality of positioning rods disposed between the first limiting plate and the second limiting plate. The first limiting plate, the second limiting plate and the positioning rods define a limiting space inside them. An insert rod for inserting a mobile phone frame is provided in the limiting space, and two adjacent mobile phone frames are separated by a spacer.

[0010] According to one example, the first drive unit includes a first transmission assembly and a first power input component, and the second drive unit includes a second transmission assembly and a second power input component. The first transmission assembly and the second transmission assembly are respectively fixed to both ends of the main shaft. The first power input component is connected to the first transmission assembly via a conveyor belt, and the second power input component is connected to the second transmission assembly via a transmission chain.

[0011] According to one example, the first transmission assembly includes a first connecting plate and a first transmission wheel, the first connecting plate and the first transmission wheel being fixed side by side to one end of the main shaft, and one end of a plurality of roller portions being distributed circumferentially at intervals along the first connecting plate and rotatably connected to the first connecting plate. The second transmission assembly includes a second connecting plate, a first gear disk, and a first synchronous pulley. The second connecting plate is fixed to the other end of the main shaft. The first gear disk and the first synchronous pulley are rotatably mounted on the main shaft and located on the outside of the second connecting plate. The other ends of the plurality of roller portions are distributed circumferentially along the second connecting plate and rotatably connected to the second connecting plate. The other end of each roller portion is provided with a second synchronous pulley that cooperates with the first synchronous pulley.

[0012] According to one example, the roller section includes a cylinder body and a cylinder cover, the top of the cylinder body is open, the cylinder cover is detachably connected to the cylinder body, and the cylinder body and the cylinder cover, when closed, form a grinding space with an octagonal cross-section. The upper part of the cylinder cover is provided with a locking part for locking the cylinder cover and the cylinder body. The locking part includes a pair of symmetrically arranged eccentric shafts and a connecting rod connected between the two eccentric shafts. An elastic rod is provided at the outer end of the eccentric shaft away from the connecting rod. A fixing plate is provided on each of the two end walls of the cylinder. The fixing plate has a groove in the horizontal direction facing the elastic rod that matches the free end of the elastic rod. By rotating the connecting rod, the eccentric shaft is driven to rotate, so that the eccentric shaft presses against the top of the cylinder cover to lock the cylinder cover and the cylinder.

[0013] According to one example, the abrasive media includes a brightener, abrasive, and pure water, wherein the brightener is selected from fatty acid derivatives or polyethylene glycol ethers, and the abrasive is selected from alumina abrasives, zirconia abrasives, or silicon carbide abrasives.

[0014] According to one example, the bottom of the first power input is provided with a flap assembly for adjusting the angle of the first power input to tension the drive belt; The bottom of the second power input component is provided with a lifting assembly for adjusting the height of the second power input component to tension the transmission chain.

[0015] According to one example, the post-processing device includes a cleaning unit, a blowing unit, and a drying unit connected in sequence. The cleaning unit is used to remove residual abrasive media from the surface of the phone frame. The blowing unit is used to blow away residual liquid from the surface and gaps of the phone frame using high-pressure airflow. The drying unit is used to dry the phone frame after the blowing treatment with hot air to remove moisture adhering to its surface.

[0016] A processing technology for grinding the mid-frame of a mobile phone includes the following steps: A stacking polishing device is used to pre-polish the mobile phone mid-frame blank to remove obvious burrs and milling marks from the surface of the blank; The pre-polished mobile phone frames are alternately stacked in the limited space of the fixture. Adjacent mobile phone frames are separated by spacer hangers. After loading, the fixture is placed into the roller section of the rolling grinding device, and grinding media is added to the roller section. Close the roller section, start the first drive section and the second drive section of the rolling grinding device. Through the difference in the tooth ratio between the first synchronous wheel and the second synchronous wheel in the second drive section, drive multiple roller sections to move circumferentially around the main shaft and rotate themselves synchronously, forming a relative rolling state, and grind the middle frame of the mobile phone for 30-40 minutes. After grinding, the fixture is removed and the phone frame is unloaded. It is then sent to the post-processing unit for cleaning and drying to obtain a qualified phone frame with a surface finish.

[0017] The present invention has the following advantages: This invention provides a processing system for grinding mobile phone mid-frames. Through a modular design of a stacking polishing device, a rolling polishing device, and a post-processing device, it achieves seamless integration from pre-treatment to finished product, solving the problems of disconnected processes and limited functionality in existing systems. A primary polishing device can be flexibly added based on the complexity of the mid-frame structure, specifically addressing the inner edge areas that are easily obscured after fixture loading. This maintains high-volume fixture loading while eliminating grinding dead zones in traditional systems, achieving full-area polishing. The post-processing device uses ultrasonic cleaning, high-pressure blowing, and hot air drying to achieve integrated clean and dry treatment of the mid-frame after grinding, reducing transfer losses and the risk of secondary contamination between processes.

[0018] The processing technology of this invention is based on a standardized process formed by the system. Through pre-grinding, composite grinding, and post-treatment, the processing cycle (CT) of a single frame is reduced to 14 seconds, and the batch processing capacity of the fixture reaches 136 pieces, increasing production capacity. Furthermore, the grinding time is only 30-40 minutes, further shortening the production cycle. Pre-polishing removes initial defects, composite motion grinding ensures surface uniformity, and ultrasonic cleaning eliminates residual impurities, resulting in a batch processing yield of over 98.8%. Defective products are concentrated in a small number of mechanically damaged items (accounting for 1.2%), with no appearance defects caused by uneven grinding or residual impurities. The process uses a PLC controller to preset grinding parameters, avoiding parameter fluctuations caused by manual operation and ensuring consistent surface roughness within the same batch, thus meeting the stringent requirements for batch quality stability in high-end mobile phone frames.

[0019] The rolling grinding device of this invention solves the problems of single motion mode and poor grinding effect of existing grinding devices by using a differentiated tooth ratio design of the synchronous wheel in the second drive unit, combined with an octagonal grinding space. The first drive unit drives the roller to revolve around the main shaft via a transmission belt, while the second drive unit drives the second transmission component via a transmission chain. Utilizing the difference in tooth ratio between the first synchronous wheel and the second synchronous wheel of the roller, the roller rotates around its own axis, simultaneously achieving a composite motion of revolution and rotation. This motion mode causes the grinding media to form multi-angle, multi-directional friction trajectories, effectively covering complex areas such as the corners of the frame and the periphery of holes, avoiding grinding dead angles caused by unidirectional friction. The octagonal cross-section grinding space of the roller increases the frequency of motion disturbance of the grinding media, reduces the flow of media along a fixed trajectory, further enhances grinding uniformity, and ensures consistent surface quality in batch processing. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the processing flow of the grinding system for mobile phone mid-frame according to the present invention.

[0021] Figure 2 This is a three-dimensional structural diagram of the rolling grinding device of the present invention.

[0022] Figure 3 This is a three-dimensional partial cross-sectional view of the rolling grinding apparatus of the present invention.

[0023] Figure 4 This is a three-dimensional structural diagram of the grinding assembly of the present invention.

[0024] Figure 5 This is a three-dimensional structural diagram of the grinding assembly of the present invention from another angle.

[0025] Figure 6 This is a three-dimensional structural schematic diagram of the first power input component of the present invention.

[0026] Figure 7 This is a three-dimensional structural schematic diagram of the second power input component of the present invention.

[0027] Figure 8 This is an exploded perspective view of the second transmission component of the present invention.

[0028] Figure 9 This is a three-dimensional structural diagram of the roller portion of the present invention.

[0029] Figure 10 This is an exploded perspective view of the roller portion of the present invention.

[0030] Figure 11 This is a three-dimensional structural diagram of the fixture of the present invention.

[0031] Figure 12 This is an exploded perspective view of the fixture of the present invention.

[0032] Figure 13 This is an exploded perspective view of the mobile phone frame and spacer bracket of the present invention.

[0033] In this design, A is a stacking and polishing device, B is a rolling grinding device, C is a post-processing device, D is a primary grinding device, 1 is a shell, 101 is an opening, 102 is a cover, 103 is a discharge port, 104 is a heat dissipation port, 105 is a controller, 106 is a support foot, 107 is a support rod, 108 is a partition plate, 2 is a grinding assembly, 201 is the first drive unit, 201a is the main shaft, 201b is the first transmission assembly, 201b1 is the first connecting plate, 201b2 is the first transmission wheel, 201c is the first power input component, 201c1 is the first motor, 201c2 is the second transmission wheel, 201c3 is the transmission belt, 201c4 is the first bearing seat, 201d is the flip plate assembly, 201d1 is the flat plate, 201d2 is the adjusting rod, 202 is the second drive unit, 202a is the second transmission assembly, and 202a1 is the second connecting plate. 202a2 is the first gear disc, 202a3 is the first synchronous pulley, 202a4 is the synchronous belt, 202a5 is the second synchronous pulley, 202a6 is the driven pulley, 202a7 is the second bearing housing, 202b is the second power input component, 202b1 is the second motor, 202b2 is the second gear disc, 202b3 is the transmission chain, 202c is the lifting assembly, 202c1 is the fixed base, and 202c2 is... Screw and nut, 203 is the roller part, 203a is the cylinder body, 203b is the cylinder cover, 203c is the grinding space, 203d is the fixture, 203d1 is the first limiting plate, 203d2 is the second limiting plate, 203d3 is the positioning rod, 203d4 is the limiting space, 203d5 is the mobile phone frame, 203d6 is the spacer hanger, 203d7 is the insertion rod, 203d8 is the hanger cover, and 203e is the locking part. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0035] Reference Figure 1 It illustrates a specific embodiment of the processing flow of a grinding system for mobile phone mid-frames, and the batch processing yield of mid-frames ground by this system reaches over 98.8%.

[0036] The processing system generally includes a stacking polishing device A, a fixture 203d, a rolling grinding device B, and a post-processing device C. Each device forms a material flow path according to the processing sequence of the mobile phone frame. The stacking polishing device A, as a pre-processing unit, pre-polishes the CNC-milled mobile phone frame blanks. By initially removing obvious burrs, milling marks, and other initial defects from the blank surface, it provides a workpiece with a uniform surface condition for the subsequent core grinding process, reducing the grinding pressure. The fixture, as a workpiece bearing and positioning component, is used to batch load multiple mobile phone frames to be ground. Precise positioning of the frames prevents workpiece displacement and collision during grinding, ensuring consistency in batch processing. The rolling grinding device B, as the core processing unit of the system, is located downstream of the stacking polishing device A. It receives the pre-polished frames loaded onto the fixture. Through the transmission mode of this embodiment, it drives the fixture to interact with the grinding media, achieving fine grinding of the frame surface. The post-processing unit C is located downstream of the rolling grinding unit B. It is used to receive the mobile phone frame after grinding, remove the grinding media, waste liquid and other impurities remaining on the surface of the frame, and dry the frame to finally obtain a qualified workpiece with a clean surface that meets the requirements of the downstream process.

[0037] The multi-layer polishing device A, serving as a pre-polishing equipment for mobile phone mid-frame prototypes, primarily uses the relative movement of multiple polishing discs to perform preliminary polishing on the mid-frame surface. This removes obvious burrs, milling marks, and oxide scale from CNC machining, providing a workpiece with a uniform surface condition for subsequent polishing processes. Existing multi-layer polishing devices A mainly include vertical multi-layer polishing machines, horizontal double-disc polishing machines, planetary polishing machines, or belt polishing machines, etc., which can be flexibly selected according to the initial surface condition of the mid-frame prototype and batch processing requirements.

[0038] The processing system can be equipped with a primary grinding device D according to the structural complexity, surface quality requirements and fixture loading characteristics of the mobile phone frame. The primary grinding device D is located downstream of the stacking polishing device A and upstream of the rolling grinding device B. The primary grinding device D performs environmentally friendly grinding on the pre-polished mobile phone frame from upstream to polish the inner edge of the mobile phone frame.

[0039] The primary grinding device D can be a disc grinder, a rotary grinder, a planetary ball mill, or a three-roll grinder, depending on the structural characteristics of the inner edge of the middle frame. For the inner edge of the middle frame, which may be obscured by the spacer fixtures during batch loading of fixtures, a grinding method adapted to complex areas is used to complete the inner edge treatment before the fixtures are loaded into the middle frame. This effectively eliminates grinding blind spots that may occur during subsequent rolling grinding, while maintaining the efficiency of high batch loading of fixtures and avoiding the impact of structural obstruction on the overall grinding quality.

[0040] Meanwhile, the primary grinding unit D can be configured with environmentally friendly grinding processes. For example, it can use biodegradable plant-based grinding fluid instead of traditional chemical grinding agents, which contains no heavy metals or volatile organic compounds, and the grinding waste liquid can be recycled after simple filtration. Alternatively, recyclable ceramic microspheres can be used as the grinding media, and the wear debris can be separated by magnetic separation for recycling and reuse, reducing solid waste generation. In addition, the unit can be equipped with a negative pressure dust collection component to collect fine dust generated during the grinding process in real time, avoiding air pollution in the workshop, thus meeting the requirements of green production while ensuring the grinding accuracy of the inner edges.

[0041] Post-processing unit C, as the final step in this processing system, is located downstream of the rolling grinding unit B. It receives the phone frame after rolling grinding, removes residual impurities from the frame surface through multi-unit collaborative processing, and dries it, providing a surface condition that meets process requirements for the frame to enter downstream manufacturing processes. Post-processing unit C mainly includes a cleaning unit, a blowing unit, and a drying unit connected in sequence. The cleaning unit removes residual grinding media and grinding waste liquid (chemical solution) from the surface and hidden areas of the phone frame. It employs ultrasonic cleaning, utilizing the impact force of microbubbles generated by the high-frequency vibration of ultrasound to achieve comprehensive, thorough cleaning.

[0042] The blowing unit is located downstream of the cleaning unit and is used to blow away the residual cleaning liquid on the surface and in the gaps of the mobile phone frame with high-pressure airflow. Its function is to quickly reduce the free water on the surface of the frame, on the one hand to prevent water from carrying residual impurities to re-attach, and on the other hand to reduce the processing load of the subsequent drying unit and shorten the overall post-processing cycle.

[0043] The drying unit, as the final step of the post-processing device C, is used to dry the mobile phone frame after it has been sprayed with hot air. A tubular dryer is used to quickly remove residual moisture from the surface of the frame, ensuring that the frame surface is dry and free of moisture, thus avoiding oxidation and rust during subsequent storage or transportation.

[0044] The mobile phone frame processed by this post-processing device C has a surface cleanliness and dryness that can precisely match the requirements of downstream manufacturers' sandblasting and anodizing processes, and the batch processing yield can stably reach over 98.8%.

[0045] The cleaning unit, blowing unit, and drying unit in the post-processing device C can be integrated into one device or arranged in series separately.

[0046] Reference Figure 2 and Figure 3 The illustration shows a specific embodiment of the rolling grinding device B, which serves as a key pre-processing equipment for the processing of the middle frame. Through controllable mechanical grinding, the rolling grinding device B removes vertical lines, burrs, and tool marks from the surface of the sample blank, optimizes the surface roughness of the middle frame, and provides qualified pre-processed workpieces for subsequent processes.

[0047] The rolling grinding device B mainly includes a housing 1, a main shaft 201a horizontally arranged inside the housing 1, and a grinding assembly 2 arranged inside the housing 1, as shown in the figure. The housing 1 has a horizontally arranged base plate, side plates extending vertically upward along the four sides of the base plate, and an arched plate connected to the top of the four side plates. The base plate, side plates and arched plates together form a closed accommodating space, the volume of which is adapted to the installation dimensions of the grinding assembly 2.

[0048] The housing 1 has heat dissipation vents 104 formed on one or both end walls, and an axial flow fan (not shown in the figure) can be built into the corresponding inner side wall of the housing 1 to dissipate the heat generated by the grinding assembly 2 during operation, preventing the drive components from overloading due to high temperature. A controller 105 is configured on the other end wall of the housing 1. The controller 105 is electrically connected to the power component of the grinding assembly 2 via wires, enabling functions such as speed adjustment, time setting, and emergency stop. Multiple support feet 106 are provided at the bottom of the housing 1, raising the bottom of the housing 1 a certain distance from the ground. An opening 101 is formed in the middle of the side wall of the housing 1, and an opening 101 is formed in the middle area of ​​one of the side plates of the housing 1. The size of this opening 101 is adapted to the loading and unloading size of the roller section 203 of the grinding assembly 2, facilitating the loading or unloading of workpieces by the operator. An openable and closable cover 102 is configured on the upper part of the opening 101, which can be closed when the grinding assembly 2 is running at high speed to prevent the grinding media from splashing or accidentally contacting the moving parts. The lower part of the opening 101 is integrally formed with an inclined downward discharge port 103. The inner diameter of the discharge port 103 gradually narrows from the end connected to the opening 101 to the outlet end, and a detachable receiving box (not shown in the figure) is provided at the outlet to collect the grinding media after grinding, which is convenient for subsequent recycling.

[0049] In an embodiment not shown, a baffle may be detachably provided at the opening 101. When the grinding assembly 2 is in a high-speed operating state, the operator can assemble the baffle at the opening 101 and cooperate with the cover 102 to form a double seal on the opening 101. This can effectively block the grinding liquid and abrasive particles that may splash during the grinding process, and also prevent personnel from accidentally touching the moving parts inside the opening 101.

[0050] Reference Figure 4 and Figure 5 The grinding assembly 2 includes a first drive unit 201, a second drive unit 202, and multiple roller units 203, forming a symmetrical layout of dual drive units and multiple roller units 203. The roller units 203 are rotatably disposed between the first drive unit 201 and the second drive unit 202. The number of roller units 203 is set to 3-6 according to mass production requirements; in this embodiment, 4 are preferred. The included angle between two adjacent roller units 203 is 90°, and the axes of all roller units 203 are parallel to the axis of the main shaft 201a and aligned with the central axis of the opening 101 of the housing 1. This ensures that the operator can directly access the fixture 203d inside the roller unit 203 through the opening 101 without adjusting the operating position. The roller units 203 are used to accommodate the fixture 203d and the grinding media and correspond to the position of the opening 101. The fixture 203d is used to load the mobile phone frame to be ground. Through controllable friction between the grinding media and the surface of the frame, defect removal and surface polishing are achieved.

[0051] On the inner walls of both sides of the opening 101 of the housing 1, partition plates 108 are vertically arranged. The two partition plates 108 divide the internal space of the housing 1 into three regions along its length: a first region near the controller 105, a second region located in the middle of the housing 1, and a third region near the heat dissipation hole of the housing 1. The first drive unit 201 is installed in the first region, and the second drive unit 202 is installed in the third region. Multiple roller units 203 are located in the second region, and the two ends of the roller units 203 pass through the two partition plates 108 respectively, and are connected to the first drive unit 201 and the second drive unit 202 for transmission.

[0052] The first drive unit 201 includes a main shaft 201a, a first transmission assembly 201b, and a first power input component 201c. The second drive unit 202 includes a second transmission assembly 202a and a second power input component 202b. The first drive unit 201 and the second drive unit 202 provide differentiated power inputs to the roller unit 203 to achieve a combined motion of circumferential revolution and self-rotation. The main shaft 201a is arranged horizontally, with one end connected to the power output end of the first transmission assembly 201b, and the other end extending horizontally and passing through the second region, connecting to the power output end of the second transmission assembly 202a, forming a central support shaft that runs through the three regions, providing a rotation center for the revolution of the roller unit 203. Multiple roller sections 203 are connected at both ends to a first transmission component 201b and a second transmission component 202a, respectively. The second transmission component 202a is provided with a first synchronous wheel 202a3, and a second synchronous wheel 202a5 is provided at one end of the roller section 203 near the second transmission component 202a. The first synchronous wheel 202a3 and the second synchronous wheel 202a5 are driven by different numbers of teeth. When the first power input component 201c and the second power input component 202b are started synchronously, the first transmission component 201b drives the roller section 203 to revolve around the main shaft 201a in a circumferential revolution. The second transmission component 202a drives the roller section 203 to rotate around its own axis through the difference in the number of teeth of the synchronous wheels. The difference in rotation speed creates a speed difference, causing the multiple roller sections 203 to roll relative to each other. This causes the internal grinding medium to form uniform and multi-angle friction on the surface of the mobile phone frame, solving the problem of uneven grinding in the traditional single motion mode.

[0053] Continue to refer to Figure 4 The first transmission assembly 201b includes a first connecting plate 201b1 and a first transmission wheel 201b2 arranged side-by-side along the axis of the main shaft 201a. They are approximately disc-shaped and coaxially fitted onto one end of the main shaft 201a. The diameter of the first connecting plate 201b1 is larger than the diameter of the first transmission wheel 201b2. On the end face of the first connecting plate 201b1 away from the first transmission wheel 201b2, four bearing mounting holes are evenly spaced circumferentially, each housing a bearing. One end of each of the multiple roller sections 203 is fixedly connected to the inner ring of the bearing, allowing the roller sections 203 to both revolve circumferentially around the main shaft 201a with the first connecting plate 201b1 and rotate on their own axis.

[0054] The first power input component 201c includes a first motor 201c1 fixedly installed on the bottom wall of the first region of the housing 1. A second transmission wheel 201c2 is fixedly attached to the output end of the first motor 201c1, and the first transmission wheel 201b2 and the second transmission wheel 201c2 are connected by a transmission belt 201c3. In this embodiment, three first wheel grooves are axially spaced on the circumferential wall of the first transmission wheel 201b2, and three second wheel grooves are also formed on the circumferential wall of the second transmission wheel 201c2. The three transmission belts 201c3 are respectively wound around the first wheel grooves and the second wheel grooves.

[0055] In addition, the two ends of the main shaft 201a are respectively equipped with a first bearing seat 201c4 and a second bearing seat 202a7. The first bearing seat 201c4 is located in the first region and is fixed on the support rod 107 on the inner wall of the first region of the housing 1. The second bearing seat 202a7 is located in the third region and is fixed on the support rod 107 on the inner wall of the third region of the housing 1 to provide stable support.

[0056] Reference Figure 6 The bottom of the first motor 201c1 is equipped with a flap assembly 201d for adjusting the angle of the first motor 201c1, thereby adjusting the tension of the transmission belt 201c3. The flap assembly 201d includes a flat plate 201d1 and an adjusting rod 201d2. The flat plate 201d1 is a rectangular plate, the top surface of which is fixedly connected to the bottom of the first motor 201c1. One side of its bottom surface is hinged to the bottom wall of the housing 1 through a hinge structure, allowing the flat plate 201d1 to rotate freely around the hinge axis, thereby driving the first motor 201c1 to adjust its angle synchronously. The adjusting rod 201d2 is a screw, the upper end of which passes vertically through an adjusting hole on the other side of the flat plate 201d1, and is detachably connected to the flat plate 201d1 through two locking nuts, which are located on the upper and lower surfaces of the flat plate 201d1 respectively. The lower end of the adjusting rod 201d2 is rotatably connected to a seat fixed to the bottom wall of the housing 1 through a rotating shaft. When tensioning the drive belt 201c3 is required, the operator can loosen the locking nut on the lower surface of the plate 201d1 and turn the locking nut on the upper surface downwards, causing the plate 201d1 to rotate downwards around the hinge. This moves the second drive wheel 201c2 away from the first drive wheel 201b2, increasing the center distance between them to tension the drive belt 201c3. After tensioning, tightening the locking nut on the lower surface fixes the position of the plate 201d1, ensuring that the drive belt 201c3 is always under proper tension.

[0057] Continue to refer to Figure 5The second transmission assembly 202a is used to transmit the rotational power of the roller section 203. It includes a second connecting plate 202a1, which has the same shape as the first connecting plate 201b1 and is coaxially fixed to the other end of the main shaft 201a. The end face of the second connecting plate 202a1 facing the roller section 203 is evenly provided with four bearing mounting holes along the circumference. Each bearing mounting hole is equipped with a bearing. The other ends of the multiple roller sections 203 are fixedly connected to the inner ring of the corresponding bearing.

[0058] Reference Figure 5 and Figure 8 The second transmission assembly 202a also includes a first gear disk 202a2 and a first synchronous pulley 202a3 rotatably mounted on the other end of the main shaft 201a. The first gear disk 202a2 and the first synchronous pulley 202a3 are fixedly connected, that is, the first gear disk 202a2 and the first synchronous pulley 202a3 can rotate synchronously around the main shaft 201a. The diameter of the first gear disk 202a2 is smaller than that of the second connecting plate 202a1. The first synchronous wheel 202a3 is rotatably mounted on the main shaft 201a through bearings, and its axial position is located between the second connecting plate 202a1 and the first gear disk 202a2, so that the first synchronous wheel 202a3 and the main shaft 201a form a relative rotational relationship. When the main shaft 201a drives the second connecting plate 202a1 and the roller part 203 to revolve, the first gear disk 202a2 and the first synchronous wheel 202a3 can rotate independently around the main shaft 201a without being affected by the revolution, thereby providing an independent power for the rotation of the roller part 203 that is decoupled from the revolution.

[0059] Each roller section 203 is equipped with a second synchronous pulley 202a5 at the other end, and is connected to the first synchronous pulley 202a3 by a synchronous belt 202a4. In this embodiment, based on the rotation of the four roller sections 203, a dual synchronous belt 202a4 is used for group transmission to ensure that the rotation speed of the four roller sections 203 is consistent. There are two synchronous belts 202a4, and each synchronous belt 202a4 drives two adjacent roller sections 203. On the side wall of the second connecting plate 202a1 between two adjacent roller sections 203, a driven wheel 202a6 is fixed by a bracket. The driven wheel 202a6, together with the second synchronous wheel 202a5 and the first synchronous wheel 202a3 of the two adjacent roller sections 203, form a triangular transmission path. The synchronous belt 202a4 is sequentially wrapped around the first synchronous wheel 202a3, the second synchronous wheel 202a5 of one of the roller sections 203, the driven wheel 202a6, and the second synchronous wheel 202a5 of the other second roller section 203, forming a closed transmission loop. In this way, the driven wheel 202a6 can change the transmission direction of the timing belt 202a4, avoiding the timing belt 202a4 from becoming loose or vibrating due to excessive span. Moreover, by driving two roller sections 203 with a single timing belt 202a4, it can be ensured that the rotation speed of the two roller sections 203 in the same group is completely consistent, thereby ensuring that the movement state of the grinding media in all roller sections 203 is synchronized and improving the consistency of grinding multiple frames at the same time.

[0060] The second transmission assembly 202a also includes a second power input component 202b fixed to the bottom wall of the housing 1, used to provide power to the second transmission assembly 202a. This component includes a second motor 202b1 fixedly mounted to the bottom wall of the third region of the housing 1. A second gear disk 202b2 is fixed to the end of the output shaft of the second motor 202b1, and is connected to the first gear disk 202a2 via a transmission chain 202b3. When the second motor 202b1 starts, power is transmitted to the first gear disk 202a2 via the transmission chain 202b3, causing the first synchronous pulley 202a3 fixed to the first gear disk 202a2 to rotate synchronously. Subsequently, the first synchronous pulley 202a3 transmits power to the second synchronous pulleys 202a5 of each roller section 203 via a synchronous belt 202a4, ultimately driving the roller section 203 to rotate around its own axis. Combined with the revolution of the roller section 203 driven by the first drive section 201, the combined motion of the revolution and rotation of the roller section 203 is finally realized, providing power for the grinding media to form a relative rolling state.

[0061] Reference Figure 7The bottom of the second motor 202b1 is equipped with a lifting assembly 202c for adjusting the height of the second motor 202b1. By adjusting the center distance between the second motor 202b1 and the first gear disk 202a2, the tension of the transmission chain 202b3 can be adjusted to ensure the stability of power transmission. The lifting assembly 202c includes a fixed base 202c1 and multiple sets of screws and nuts 202c2. The fixed base 202c1 is located at the bottom of the second motor 202b1, and the multiple sets of screws and nuts 202c2 are connected between the fixed base 202c1 and the bottom wall of the housing 1, used to adjust the height of the second motor 202b1 to tension the transmission chain 202b3. The fixed base 202c1 is a plate-shaped structure and parallel to the bottom wall of the housing 1. Shaft holes for cooperating with screws are opened at the four corners of the fixed base 202c1, and the four sets of screws and nuts 202c2 are assembled one-to-one at the shaft holes to form a symmetrical four-point support structure.

[0062] The upper end of the screw is vertically inserted into the shaft hole of the fixed base 202c1, and the lower end of the screw is fixed to the bottom wall of the housing 1. Two adjusting nuts are fitted onto the screw, located on the upper and lower sides of the fixed base 202c1 respectively. The nut below the fixed base 202c1 is a support nut, used to support the weight of the fixed base 202c1 and the second motor 202b1. The nut above the fixed base 202c1 is a locking nut, used to lock the position of the fixed base 202c1 after height adjustment to prevent loosening. When it is necessary to tension the transmission chain 202b3, the operator can first simultaneously loosen the support nuts on the four sets of screws, and then simultaneously tighten the four sets of locking nuts, causing the locking nuts to move downwards along the screws. This pushes the fixed base 202c1, causing the second motor 202b1 to lift downwards as a whole, increasing the center distance between the second gear disk 202b2 and the first gear disk 202a2 at the output end of the second motor 202b1, thus gradually tensioning the transmission chain 202b3. After confirming that the chain tension meets the requirements, tighten the four sets of locking nuts simultaneously to lock the position of the fixing seat 202c1.

[0063] Reference Figure 9 and Figure 10 The figure illustrates one specific embodiment of the roller section 203. As shown, the roller section 203 includes a cylinder body 203a and a cylinder cover 203b. The top of the cylinder body 203a is open, and its cross-section is pentagonal. The cylinder cover 203b is a cover plate structure that cooperates with the cylinder body 203a, and its cross-section is triangular. It is fixed by detachable connection methods such as snap-fit ​​and keyway. For example, a snap-fit ​​seat is provided at the edge of the opening 101 of the cylinder body 203a, and an elastic snap is provided at the corresponding position of the cylinder cover 203b. After they are snapped together, it ensures that the cylinder cover 203b will not loosen due to vibration during the grinding process, and also facilitates quick opening and closing to take out and put in the fixture 203d.

[0064] After the cylinder 203a and the cylinder cover 203b are fully closed, a grinding space 203c with a regular octagonal cross-section is formed inside. Its inner diameter is 230mm, and its length is adapted to the size of the fixture 203d. Compared to traditional circular or hexagonal rollers, the octagonal structure allows the grinding media to form more complex turbulent motion through the guiding effect of the corners, avoiding grinding dead zones. The grinding space 203c contains the fixture 203d for loading the mobile phone mid-frame 203d5 to be ground, and the grinding media, which is a mixture of brightener, abrasive, and pure water in a specific ratio. In this embodiment, the abrasive particle size is 4mm-6mm, and the single-batch loading is 6kg, which can meet the batch grinding needs of 1200 mobile phone mid-frames 203d5. The abrasive is selected from one or more of alumina abrasives, zirconia abrasives, or silicon carbide abrasives. The polishing agent is added in single applications of 150ml. Through emulsification, dispersion, and penetration, it emulsifies metal debris generated during the polishing process and disperses abrasive particles to prevent agglomeration. Simultaneously, it penetrates into the tiny depressions and gaps between abrasive particles on the phone's frame surface, reducing the coefficient of friction between the abrasive and the frame surface, minimizing polishing scratches, and improving the uniformity and gloss of the frame's surface. The polishing agent is selected from neutral polishing agents, such as fatty acid derivatives and polyethylene glycol ethers. Pure water is used as the carrier medium, and the addition amount is based on completely immersing the fixture for 203 days.

[0065] The cylinder cover 203b is detachably connected to the cylinder body 203a. The cross-section of the cylinder body 203a is pentagonal, and the cross-section of the cylinder cover 203b is triangular. When the cylinder body 203a and the cylinder cover 203b are closed, they together form an octagonal cross-section grinding space 203c. The grinding space 203c contains the fixture 203d and the grinding media, which includes a brightener, abrasive, and pure water. The drum rotation speed is 0-168 r / min, the drum inner diameter is 230 mm, the abrasive is 4 mm-6 mm, 6 kg of 4-6 mm abrasive can produce 1200 pieces, the grinding time is 30 min, the grinding frequency is 35 Hz, the brightener is 150 ml, and the abrasive quantity is 6 kg. Processing efficiency: number of cavities: 134 pieces, processing CT: 14 s / piece. 2600 pieces were produced, 2570 pieces were good, yield rate was 98.8%, and 30 pieces were defective. In terms of defect details, 20 pieces were damaged (three defects), accounting for 1.2%.

[0066] Reference Figure 11-13The diagram shows a fixture 203d structure adapted to the roller section 203. The fixture 203d is used to achieve the orderly stacking and fixing of the mobile phone mid-frame 203d5. The fixture 203d includes a first limiting plate 203d1 and a second limiting plate 203d2 that are parallel to each other. Both are circular plate structures. The first limiting plate 203d1 and the second limiting plate 203d2 are detachably connected by four positioning rods 203d3 that are circumferentially spaced. The positioning rods 203d3 are cylindrical structures. One end of the positioning rod 203d3 is fixedly connected to the second limiting plate 203d2, and the other end is detachably connected to the first limiting plate 203d1. Their interiors are configured to form a cylindrical limiting space 203d4 for stacking the mobile phone mid-frame 203d5. The circumferentially distributed spacing of the positioning rods 203d3 is equal, which can provide radial limiting for the stacked mid-frame and prevent the mid-frame from shifting during the grinding process.

[0067] A rod 203d7 is vertically fixed at the center of the second limiting plate 203d2. Its length is the same as that of the positioning rod 203d3. The rod 203d7 is used to axially insert the phone frame 203d5 and the spacer 203d6. Its top end is detachably connected to the center of the first limiting plate 203d1, forming a dual positioning structure of a central axis and a circumferential positioning rod 203d3. The spacer 203d6 includes a rectangular base whose edge dimensions are approximately the same as the inner dimensions enclosed by the rectangular border of the phone frame 203d5. It can be embedded inside the frame to achieve axial separation. A through hole is formed in the center of the base to mate with the rod 203d7, and protrusions are provided at both ends. The mobile phone mid-frame 203d5 includes a rectangular frame and a central substrate. A through hole is formed in the center of the substrate for the insertion rod 203d7 to pass through. Both ends of the substrate are provided with locking holes that cooperate with the protrusions of the spacer 203d6. During assembly, the protrusions are engaged in the locking holes to achieve precise positioning of the mid-frame and the spacer 203d6, while ensuring that the spacing between adjacent mid-frames is the same. In this embodiment, the spacing between adjacent mid-frames is 4mm-14mm, preferably 4mm, to ensure that the grinding medium can flow fully into the gap, while increasing the amount of mobile phone mid-frame 203d5 loaded on the fixture 203d.

[0068] In addition, a hanging cover 203d8 is provided on the uppermost mobile phone frame 203d5 near the first limiting plate 203d1. A through hole is opened in the middle of the cover for the insertion rod 203d7 to pass through, which is used to axially limit the uppermost frame. The distance between the first limiting plate 203d1 and the second limiting plate 203d2 is approximately equal to the length of the grinding space 203c of the roller part 203, ensuring that there is no axial shaking after the fixture 203d is installed, further improving the grinding stability.

[0069] The upper part of the cylinder cover 203b is also equipped with a locking part 203e to prevent the cylinder cover 203b from loosening due to the centrifugal force generated by the high-speed rotation of the roller part 203 during the grinding process. The locking part 203e has a pair of symmetrically arranged eccentric shafts connected by a cylindrical connecting rod. A rotating wrench is provided on the outer wall of the connecting rod, allowing the operator to drive the eccentric shafts to rotate by turning the wrench. In this embodiment, an elastic rod is also provided at the outer end of the eccentric shaft away from the connecting rod, and the free end of the elastic rod forms an arc-shaped guide head. Fixing plates are respectively provided on the two end walls of the cylinder body 203a, and the fixing plates have horizontally formed grooves on the side facing the elastic rod, which cooperate with the free end of the elastic rod.

[0070] When locking the cap 203b is required, the operator first places the cap 203b over the top opening of the cylinder 203a, ensuring that the edge of the cap 203b is completely flush with the edge of the opening of the cylinder 203a. Then, the operator moves the elastic rod to both sides, inserting the free end of the elastic rod into the corresponding slots of the fixing plates at both ends of the cylinder 203a. After releasing the elastic rod, the elastic rod, through its own rebound force, presses tightly against the inner wall of the slot, achieving axial positioning of the cap 203b. At this time, the axis of the eccentric shaft remains parallel to the axis of the cylinder 203a. Next, the operator holds the wrench and rotates the connecting rod clockwise around the axis of the eccentric shaft. Due to the eccentricity between the axis of the eccentric shaft and its outer circumference, the outer circumferential surface of the eccentric shaft gradually presses against the top edge of the cylinder cover 203b during rotation. As the rotation angle increases, the radial clamping force of the eccentric shaft on the cylinder cover 203b gradually increases until the maximum outer diameter of the eccentric shaft is tightly fitted with the edge of the cylinder cover 203b, forming a mechanical locking state. Thus, the eccentric clamping action of the eccentric shaft counteracts the centrifugal force generated by the rotation of the roller section 203, preventing the cylinder cover 203b from shifting or loosening during the grinding process. In addition, a rotating shaft is fixed on the outer wall of the fixed plate, and the free end of the rotating shaft is detachably installed in the bearing mounting hole of the first connecting plate 201b1 or the second connecting plate 202a1.

[0071] The first synchronous pulley 202a3 and the second synchronous pulley 202a5 are driven by different numbers of teeth, forming a tooth ratio of 1:1.05 to 1:1.15. In this embodiment, the first synchronous pulley 202a3 has 53 teeth, and the second synchronous pulley 202a5 has 57 teeth, resulting in a tooth ratio of 53:57. According to the principle that fewer teeth in a synchronous belt drive result in higher rotational speed, the second synchronous pulley 202a5 rotates at a lower speed than the first synchronous pulley 202a3, causing the rotational speed of the roller section 203 to be lower than its circumferential revolution speed around the main shaft 201a. This revolution, as the dominant motion, uses centrifugal force to stably press the grinding media against the inner wall of the roller, forming a continuous main circulation and ensuring that the entire surface of the middle frame receives uniform grinding pressure. A lower rotational speed, acting as an auxiliary disturbance, can break the symmetry of the main circulation to avoid grinding dead zones caused by a single trajectory, while also preventing turbulent media movement due to excessive rotation. If the rotational speed is too high, it may cause excessive centrifugal accumulation of the grinding media or excessive local impact, resulting in uneven wear on the middle frame surface. By adjusting the speed ratio of revolution-driven to rotation-assisted, the impact intensity of the abrasive on complex structures can be precisely controlled while ensuring overall grinding efficiency, achieving a synergy between large-area uniform grinding and precise finishing of details.

[0072] During operation, this speed difference causes two coupled motions in the roller section 203. Driven by the first transmission assembly 201b, all roller sections 203 revolve circumferentially around the main shaft 201a. Simultaneously, each roller section 203 rotates around its own axis under the power transmitted through the synchronous pulley by the second transmission assembly 202a. Due to the difference in gear ratio, the rotational and circumferential speeds form a non-linear relationship. This combined motion creates a complex flow field within the grinding media of the roller section 203. The centrifugal force of the circumferential motion pushes the media towards the inner wall, forming a main circulation flow along the cylinder wall. The tangential force generated by the rotation breaks the symmetry of the main circulation flow, giving the abrasive near the middle frame surface an additional radial impact velocity. The relative rolling of multiple roller sections due to the difference in gear ratio further interferes with adjacent flow fields, intensifying the turbulence of the media and allowing the abrasive to impact the surface to be ground from multiple angles.

[0073] As the phone's mid-frame 203d5 moves within the roller section along with the fixture 203d, the periodic centrifugal force changes caused by its revolution create a pulsating contact pressure between the mid-frame and the abrasive, overcoming the problem of abrasive penetration into vertical grooves under traditional fixed rotation speeds. The tangential friction generated by its rotation causes the abrasive to move in a spiral motion along the mid-frame surface. Combined with the corner guidance of the octagonal grinding space 203c, this allows for uniform grinding of complex structures such as right-angled edges and curved transition areas of the mid-frame. The differentiated tooth ratio of the synchronous gears ultimately creates a gradient in the abrasive impact frequency across different areas of the mid-frame surface, efficiently removing vertical groove defects while avoiding dimensional accuracy loss due to over-grinding.

[0074] Return to reference Figure 2 A controller 105 is mounted on the outer wall of the housing 1. The controller 105 is electrically connected to the first power input component 201c and the second power input component 202b, respectively. It can receive motor operating parameters in real time and output control signals to achieve independent control of the circumferential rotation speed and the self-rotation speed of the drum 203. The controller 105 is a PLC control unit, which is equipped with a control display screen and physical operation buttons. It can display key parameters such as the current grinding progress, drum revolution / rotation speed, running time, and motor current in real time. The physical buttons include, but are not limited to, emergency stop button, start / pause button, and speed adjustment knob, which are used to deal with emergencies or make quick parameter adjustments.

[0075] The PLC controller 105 has multiple built-in preset grinding programs. Operators can call the corresponding program based on the model of the frame to be processed. The controller 105 will automatically control the output frequency of the first motor 201c1 and the second motor 202b1 according to preset parameters. In addition, the controller 105 integrates a protection unit. When abnormal speed is detected due to a loose drive belt 201c3 / chain, motor overload, or the cover 102 not being closed, an audible and visual alarm will be immediately triggered, and the motor power will be automatically cut off to prevent equipment damage or safety accidents. All operational data is stored in the controller 105's local memory and can be exported via USB interface.

[0076] Based on the above processing system, a processing technology for grinding the mid-frame of a mobile phone is provided, including the following steps: Pre-polishing of mobile phone mid-frame prototype The mobile phone mid-frame blank after CNC milling is pre-polished using a multi-layer polishing device A. The surface of the blank is initially polished by the relative movement of multiple polishing discs, focusing on removing obvious burrs, milling marks and oxide scale, so that the surface of the mid-frame forms a uniform initial state.

[0077] Mounting fixture for the mid-frame of the phone to be ground The second limiting plate 203d2 is placed horizontally, and the mobile phone frame 203d5 and the spacer hanger 203d6 are loaded by alternating stacking. First, the through hole of the substrate of one mobile phone frame 203d5 is aligned with the insertion rod and inserted, so that the rectangular edge of the frame fits against the second limiting plate 203d2. Then, the through hole of the base of one spacer hanger 203d6 is aligned with the insertion rod and inserted, ensuring that the protrusions at both ends of the base are engaged in the locking holes of the frame substrate, achieving axial positioning and physical separation from adjacent frames. This process is repeated until the number of acupoints designed for the fixture 203d is reached. The upper cover 203d8 of the hanger is placed on the top mobile phone frame, and the first limiting plate 203d1 is connected and fixed to the second limiting plate 203d2 through the positioning rod 203d3. The other end of the insertion rod 203d7 is inserted into the center hole of the first limiting plate 203d1, completing the sealed loading of the fixture 203d and ensuring that the frame does not shift or collide during the grinding process.

[0078] Loading and sealing of the jig and grinding media drum section Open the cover 102 of the housing 1 of the rolling grinding device B and the cylinder cover 203b of the roller section 203, ensuring that the octagonal grinding space 203c is clean and free of impurities. Insert the fixture 203d, which has been loaded with the mobile phone frame 203d5, into the octagonal grinding space 203c of the roller section 203. Then, add grinding media into the grinding space according to the preset ratio. The abrasive should be 4mm-6mm in diameter, with a single addition of 6kg. Add 150ml of brightener and pure water to completely submerge the fixture, ensuring that the media fully coats the surface of the frame. Close the cylinder cover 203b of the roller section. The locking part 203e on the upper part of the cylinder cover 203b engages with the groove of the end wall fixing plate of the cylinder body to achieve a sealed lock between the cylinder cover 203b and the cylinder body 203a. Then close the cover 102 of the housing, completing the addition and sealing operation of the fixture 203d and the grinding media.

[0079] PLC-controlled composite motion grinding The controller 105 touchscreen calls the preset grinding parameters, setting the circumferential revolution speed of the roller section 203 around the main shaft 201a to 130-140 r / min, the grinding frequency to 35 Hz, and the grinding time to 30-40 min per cycle. The controller outputs control signals to the first power input component 201c and the second power input component 202b. The first motor 201c1 drives the first transmission component 201c2 through the transmission belt, causing the roller section 203 to revolve around the main shaft 201a. The second motor 202b1 drives the second transmission component 202a through the transmission chain 202b3, causing the first gear disk 202a2 and the first synchronous pulley 202a3 to rotate. The rotation is then transmitted to the second synchronous pulley 202a5 of the roller section 203 through the synchronous belt 202a4, causing the roller section 203 to rotate around its own axis. Due to the transmission between the first synchronous wheel 202a3 and the second synchronous wheel 202a5 and the difference in the number of teeth, the roller section 203 forms a relative rolling state under the combined action of revolution and rotation. Under the combined motion, the grinding medium generates multi-angle and multi-directional friction on the surface of the mobile phone frame 203d5, gradually removing vertical lines and fine burrs from the surface of the frame, and achieving uniform surface roughness treatment.

[0080] Unloading and post-processing after grinding When the controller 105 indicates that grinding is complete, the system automatically cuts off the power input. After the roller section 203 has completely stopped moving, the operator sequentially opens the housing 1 cover 102 and the roller section 203 cylinder cover 203b to remove the internal fixture 203d. The fixture 203d is transferred to the post-processing unit C for sequential cleaning, blowing, and drying. The ultrasonic cleaning unit removes residual grinding media and chemicals from the surface and crevices of the middle frame. The high-pressure airflow from the blowing unit removes residual liquid from the surface and hidden areas. The hot air drying unit ensures that the middle frame surface is dry and free of moisture. After post-processing is completed, the fixture is disassembled and the phone middle frame is unloaded, resulting in a surface-treated product that can directly proceed to the sandblasting and anodizing processes of downstream manufacturers.

[0081] Batch test data shows that the jig 203d of this process can process 136 pieces of mid-frame in a single batch, with a processing cycle (CT) of only 14 seconds per piece. In the test of 2600 pieces of mobile phone mid-frames, the number of good products reached 2570 pieces, with a yield rate as high as 98.8%. The defective products were mainly mechanical damage such as scratches and bumps (only 30 pieces), which fully verified the practicality and reliability of this process in improving grinding efficiency and ensuring processing quality.

[0082] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention. The embodiments described in this disclosure are intended as non-limiting examples, and other embodiments may take various and alternative forms. Furthermore, the drawings are not necessarily to scale and may present simplified expressions of various features of the present disclosure, including, for example, specific dimensions, orientations, positions, and shapes. Details associated with such features will be determined in part by the intended application and usage environment of the described embodiments.

[0083] The detailed description and accompanying drawings are supporting and descriptive of this teaching, but the scope of this teaching is defined only by the claims. While the best mode and some other embodiments for carrying out this teaching have been described in detail, various alternative designs and embodiments exist for practicing the teaching as defined in the appended claims. Furthermore, this disclosure expressly includes combinations and sub-combinations of the elements and features set forth above and below.

Claims

1. A processing system for grinding the mid-frame of a mobile phone, characterized in that, include: A stacking and polishing device used for pre-polishing mobile phone mid-frame blanks; A fixture for mounting multiple mobile phone frames to be ground; A rolling grinding device, located downstream of the stacking polishing device, comprises: The housing has an openable and closable cover on its side wall; A main shaft horizontally disposed within the housing; The grinding assembly disposed within the housing includes a first driving part, a second driving part, and a plurality of roller parts. The first driving part and the second driving part are respectively mounted at both ends of the main shaft. The roller parts are rotatably disposed between the first driving part and the second driving part and are distributed at intervals along the circumference of the main shaft to accommodate the fixture and the grinding media. The second drive unit has a second transmission assembly, which has a first synchronous wheel. The roller part is provided with a second synchronous wheel at one end near the second transmission assembly. The first synchronous wheel and the second synchronous wheel are connected to each other and have different numbers of teeth. The first drive unit drives the roller part to move circumferentially around the main shaft. The second drive unit drives the roller part to rotate by the difference in the number of teeth of the synchronous wheels, so that multiple roller parts form a relative rolling state to grind the mobile phone frame in the fixture. A post-processing device, located downstream of the rolling grinding device, is used to receive the ground mobile phone frame for cleaning and drying the surface of the mobile phone frame.

2. The processing system according to claim 1, characterized in that, It also includes a primary grinding device, which is located downstream of the stacking polishing device and upstream of the rolling grinding device. The primary grinding device performs environmentally friendly grinding on the pre-polished mobile phone frame from upstream to polish the inner edge of the mobile phone frame.

3. The processing system according to claim 1, characterized in that, The fixture includes a first limiting plate and a second limiting plate that are parallel to each other, and a plurality of positioning rods disposed between the first limiting plate and the second limiting plate. The first limiting plate, the second limiting plate and the positioning rods define a limiting space inside them. An insert rod for inserting a mobile phone frame is provided in the limiting space, and two adjacent mobile phone frames are separated by a spacer.

4. The processing system according to claim 1, characterized in that, The first drive unit includes a first transmission assembly and a first power input component, and the second drive unit includes a second transmission assembly and a second power input component. The first transmission assembly and the second transmission assembly are respectively fixed to both ends of the main shaft. The first power input component is connected to the first transmission assembly via a conveyor belt, and the second power input component is connected to the second transmission assembly via a transmission chain.

5. The processing system according to claim 4, characterized in that, The first transmission assembly includes a first connecting plate and a first transmission wheel. The first connecting plate and the first transmission wheel are fixed side by side to one end of the main shaft. One end of a plurality of roller portions is distributed circumferentially along the first connecting plate and rotatably connected to the first connecting plate. The second transmission assembly includes a second connecting plate, a first gear disk, and a first synchronous pulley. The second connecting plate is fixed to the other end of the main shaft. The first gear disk and the first synchronous pulley are rotatably mounted on the main shaft and located on the outside of the second connecting plate. The other ends of the plurality of roller portions are distributed circumferentially along the second connecting plate and rotatably connected to the second connecting plate. The other end of each roller portion is provided with a second synchronous pulley that cooperates with the first synchronous pulley.

6. The processing system according to claim 1, characterized in that, The roller section includes a cylinder body and a cylinder cover. The top of the cylinder body is open, and the cylinder cover is detachably connected to the cylinder body. When the cylinder body and the cylinder cover are closed, they form a grinding space with an octagonal cross-section. The upper part of the cylinder cover is provided with a locking part for locking the cylinder cover and the cylinder body. The locking part includes a pair of symmetrically arranged eccentric shafts and a connecting rod connected between the two eccentric shafts. An elastic rod is provided at the outer end of the eccentric shaft away from the connecting rod. A fixing plate is provided on each of the two end walls of the cylinder. The fixing plate has a groove in the horizontal direction facing the elastic rod that matches the free end of the elastic rod. By rotating the connecting rod, the eccentric shaft is driven to rotate, so that the eccentric shaft presses against the top of the cylinder cover to lock the cylinder cover and the cylinder.

7. The processing system according to claim 1, characterized in that, The grinding media includes a brightener, abrasive, and pure water. The brightener is selected from fatty acid derivatives or polyethylene glycol ethers, and the abrasive is selected from alumina abrasive grains, zirconia abrasive grains, or silicon carbide abrasive grains.

8. The processing system according to claim 4, characterized in that, The bottom of the first power input component is provided with a flap assembly for adjusting the angle of the first power input component to tension the transmission belt; The bottom of the second power input component is provided with a lifting assembly for adjusting the height of the second power input component to tension the transmission chain.

9. The processing system according to claim 1, characterized in that, The post-processing device includes a cleaning unit, a blowing unit, and a drying unit connected in sequence. The cleaning unit is used to remove residual abrasive media from the surface of the mobile phone frame. The blowing unit is used to blow away residual liquid from the surface and gaps of the mobile phone frame using high-pressure airflow. The drying unit is used to dry the mobile phone frame after the blowing treatment with hot air to remove the moisture adhering to its surface.

10. A processing technology for grinding the mid-frame of a mobile phone, characterized in that, Includes the following steps: A stacking polishing device is used to pre-polish the mobile phone mid-frame blank to remove obvious burrs and milling marks from the surface of the blank; The pre-polished mobile phone frames are alternately stacked in the limited space of the fixture. Adjacent mobile phone frames are separated by spacer hangers. After loading, the fixture is placed into the roller section of the rolling grinding device, and grinding media is added to the roller section. Close the roller section, start the first drive section and the second drive section of the rolling grinding device. Through the difference in the tooth ratio between the first synchronous wheel and the second synchronous wheel in the second drive section, drive multiple roller sections to move circumferentially around the main shaft and rotate themselves synchronously, forming a relative rolling state, and grind the middle frame of the mobile phone for 30-40 minutes. After grinding, the fixture is removed and the phone frame is unloaded. It is then sent to the post-processing unit for cleaning and drying to obtain a qualified phone frame with a surface finish.

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