Automatic polishing process for metal soup spoon with handle

Abstract

The invention discloses an automated polishing process for a metal soup spoon with a handle, and relates to the technical field of polishing. In the automated polishing process for the metal soup spoon with a handle, a robot clamps the product and performs continuous rough polishing and fine polishing on the handle and the spoon head in sequence, thereby avoiding the trouble of repeatedly clamping the soup spoon and improving polishing efficiency. By combining continuous rough and fine polishing, over-polishing of the thin-walled spoon head is avoided, thereby reducing thickness loss, while under-polishing of the handle results in residual oxide scale. This avoids weld pores that are not promptly processed in the rough polishing stage from possibly expanding into visible defects during fine polishing, thereby reducing scrap rate. At the same time, continuous rough polishing avoids heat storage and conduction from a high heat capacity area (handle) to a low heat capacity area (spoon head edge) to induce sensitization of stainless steel, and prevents the formation of overlapping stress areas at the joints during uniform rough polishing, thereby preventing microcracks from being caused by uneven stress release after fine polishing. At the same time, the difference in roughness between a curved surface and a flat surface is greatly reduced, the occurrence of uneven grain is reduced, and surface consistency is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of polishing, in particular to an automatic polishing process for a metal soup spoon with a handle. Background Art

[0002] Metal tableware is an indispensable necessity in our daily life. Currently, the metal tableware on the market includes soup spoons, shovels, etc.

[0003] The existing Chinese invention patent published on January 10, 2025, with the announcement number CN119017030B, is an automatic production process for metal soup spoons. It solves the problems that the flat handle is weak in strength, easily deformed during transportation and use, and manually stretched by hand, which not only has low work efficiency but also poses safety hazards. The head and handle of the spoon are punched out as a whole from a stainless steel plate. When the connection between the handle and the spoon head is bent into a certain arc, it is easy to break during the processing. The strength of the connection after bending is weak, and it is also easy to break during use. The head of the spoon can only be shallowly stretched, and a deeper hemispherical spoon head cannot be made.

[0004] After the semi-finished soup spoon is produced through the above production process, it needs to be polished and ground. The existing soup spoon polishing and grinding system is shown in a stainless steel soup spoon grinding system disclosed in the Chinese utility model patent published on April 6, 2018, with the publication number CN207189452U. Through the visual monitoring component, it is respectively coordinated with the feeding conveyor belt, the unloading conveyor belt, the spoon handle processing floating component, the soup spoon rough processing floating component, the soup spoon fine processing floating component, the main grasping robot, and the diversion grasping robot structure. It can automatically realize the workpiece loading, the workpiece spoon handle grinding and drawing, the workpiece upper half of the soup spoon rough grinding, the soup spoon lower half rough grinding, the soup spoon inside rough grinding, the workpiece upper half of the soup spoon fine grinding, the soup spoon lower half fine grinding, the soup spoon inside fine grinding, the workpiece unloading and other processes, intelligent operation, high efficiency, reduce safety hazards, and improve product processing quality.

[0005] This polishing method first performs uniform rough grinding and then fine grinding, but has the following problems: (1) the soup spoon needs to be clamped repeatedly, which makes the polishing efficiency low; (2) the uniform rough polishing parameters are difficult to adapt to the characteristics of multiple regions, resulting in over-polishing of the thin-walled spoon head (thickness loss > 5%) and under-polishing of the handle (residual oxide scale). The weld pores that are not treated in time during the rough polishing stage may expand into visible defects (diameter > 0.2mm) during fine polishing, increasing the scrap rate by 3%-5%; (3) continuous rough polishing causes the heat stored in the high heat capacity area (handle) to be transferred to the low heat capacity area (spoon head edge), and the local temperature can reach above 150℃, causing stainless steel sensitization (carbide precipitation). The uniform rough polishing forms overlapping stress areas (-250MPa) at the joints, and micro cracks (depth > 10μm) may be caused by uneven stress release after fine polishing; (4) the difference in roughness between the curved surface and the flat surface is ±30%, which is prone to uneven texture and poor surface consistency. Summary of the Invention

[0006] In order to overcome the shortcomings of the existing technology, the present invention provides an automated polishing process for a metal soup spoon with a handle to solve the problems of low polishing efficiency, over-polishing of the thin-walled spoon head and under-polishing of the handle, increased scrap rate, microcracks and poor surface consistency.

[0007] To solve the above technical problems, the present invention provides the following technical solution: an automated polishing process for a metal soup spoon with a handle, the metal soup spoon comprising a spoon head, a handle precision casting, and a handle portion, the two ends of the handle precision casting being welded to the handle portion and the spoon head, respectively, the connection between the handle precision casting and the spoon head having two arc-shaped welds, the spoon head comprising a spoon head concave portion and a spoon head convex portion, the automated polishing process comprising the following steps:

[0008] 1. Cleaning before polishing: Clean the metal spoon to be polished after welding thoroughly;

[0009] 2. Weld flattening: The weld of the polished metal spoon is flattened by profiling and punching;

[0010] 3. Positioning: Place the metal spoon to be polished on the tooling;

[0011] Fourth: Polishing of the handle: The metal spoon to be polished is grabbed by the manipulator picking device, and the handle is radially polished and brushed to obtain uniform radial lines;

[0012] Five: Spoon head polishing: including the polishing and brushing of the concave part of the spoon head and the convex part of the spoon head. The polishing of the concave part of the spoon head includes polishing and brushing the spoon head mouth, the connection between the concave part of the spoon head and the handle, and the surface of the concave part of the spoon head in sequence. The polishing of the convex part of the spoon head includes polishing and brushing the connection between the convex part of the spoon head and the handle, and the surface of the convex part of the spoon head in sequence.

[0013] 6. Post-polishing cleaning: Use environmentally friendly cleaning agents and pure water combined with ultrasonic waves to clean the surface residue of the product through the cleaning production line.

[0014] Preferably, in step five, a belt sander with a 15 mm wide, 180# grit belt and a belt sander with a 20 mm wide, 240# grit belt are used to polish the weld at the connection between the spoon head recess and the handle.

[0015] Preferably, in step five, a belt sander with a 20 mm wide, 240# grit ring sanding belt, a belt sander with a 20 mm wide, 240# grit belt, and a belt sander with a 20 mm wide, 240# grit nylon belt are sequentially used to polish the concave surface of the spoon head.

[0016] Preferably, in step five, a belt sander with a 15 mm wide, 180# grit ring sander and a belt sander with a 57 mm wide, 180# grit ring sander are used to polish the weld at the connection between the spoon head protrusion and the handle.

[0017] Preferably, in step five, a belt sander with a 57 mm wide, 180# grit ring sander, a belt sander with a 57 mm wide, 240# grit ring sander, a belt sander with a 20 mm wide, 240# belt sander, and a belt sander with a 20 mm wide, 240# grit nylon belt are used to polish the convex surface of the spoon head.

[0018] Preferably, in step five, a belt sander with a 20 mm wide, 180# grit ring belt is used to polish the spoon head opening.

[0019] Preferably, the surface roughness of the handle portion, the surface of the concave portion of the spoon head, and the surface roughness of the convex portion of the spoon head are all controlled within Ra0.8um.

[0020] Preferably, it also includes several polishing devices, the manipulator material picking device is a spoon head adsorption and rotating device, and a first turnover device, a workpiece exchange device, and a second turnover device are sequentially arranged between two adjacent spoon head adsorption and rotating devices. The first turnover device is provided with a first turnover station, and the first turnover station circulates between the two adjacent spoon head adsorption and rotating devices. The first turnover station adsorbs the convex or concave surface of the spoon head. The second turnover device is provided with a second turnover station, and the second turnover station circulates between the two adjacent spoon head adsorption and rotating devices. The second turnover station adsorbs the concave or convex surface of the spoon head. The workpiece exchange device is used to exchange the spoon head close to the side of the first turnover device to the side close to the second turnover device, and exchange the direction of the concave surface of the spoon head. The spoon head adsorption and rotating device is used to adsorb or place the spoon head from the first turnover device, the workpiece exchange device, and the second turnover device, and can drive the spoon head to the polishing device for self-rotation polishing.

[0021] Preferably, in step four: the spoon head adsorption rotating device adsorbs and drives the metal soup spoon to the nylon wheel polishing machine position, starts the nylon wheel motor to drive the nylon wheel to rotate at 300 rpm, and the spoon head adsorption rotating device rotates radially with the handle part, contacts with the nylon wheel for progressive radial surface drawing.

[0022] Preferably, in step 2: the mold required for flattening the weld includes:

[0023] Next template;

[0024] A support member, the support member is fixed on the lower template, the size of the top surface of the support member is larger than the size of the handle precision casting, and the top surface of the support member is provided with a contour of the handle precision casting;

[0025] A punch having a notch formed on one end of the punch facing the support member;

[0026] A pressing block, the pressing block being fixed in the notch and being located directly above the support member;

[0027] When the mold is closed, the two arc-shaped welds respectively abut against the pressing block and the supporting member.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention performs continuous rough polishing and fine polishing on the handle and the spoon head in sequence, thereby avoiding the trouble of repeatedly clamping the soup spoon and improving polishing efficiency. Through the combination of continuous rough polishing and fine polishing, the thin-walled spoon head is avoided from being over-polished and thickness loss is reduced, while the handle is under-polished and residual oxide scale is left. The weld pores that are not promptly processed in the rough polishing stage may be expanded into visible defects during fine polishing, thereby reducing the scrap rate. At the same time, continuous rough polishing is avoided so that the high heat capacity area (handle) is not stored and conducted to the low heat capacity area (spoon head edge), causing sensitization of stainless steel, and uniform rough polishing is prevented from forming overlapping stress areas at the joint, which may cause micro cracks due to uneven stress release after fine polishing. At the same time, the difference in roughness between the curved surface and the flat surface is greatly reduced, the occurrence of uneven texture is reduced, and surface consistency is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic structural diagram of the polishing device, the manipulator material taking device, the first turnover device, the workpiece exchange device and the second turnover device of the present invention;

[0031] Figure 2 A schematic diagram of the mold structure required for weld flattening of the present invention;

[0032] Figure 3 This is a schematic diagram of the structure of the upper die base, punch, notch, pressing block and guide column of the present invention;

[0033] Figure 4This is a schematic structural diagram of the lower die base, lower die plate, support member, support block, positioning column, pad block and clamping mechanism of the present invention;

[0034] Figure 5 This is a schematic structural diagram of the pressing mechanism of the present invention;

[0035] Figure 6 This is a schematic diagram of the structure of the soup spoon after the handle, the precision casting of the handle and the spoon head are assembled;

[0036] Among them: 1. Lower die base; 2. Lower template; 3. Upper die base; 4. Punch; 41. Notch; 42. Pressing block; 5. Support member; 6. Support block; 7. Positioning column; 8. Pad; 9. Guide column; 10. Clamping mechanism; 101. First support plate; 102. First connecting rod; 103. Second connecting rod; 104. Third connecting rod; 105. Fixed block; 110. Polishing device; 11. Manipulator picking device; 12. First turnover device; 13. Second turnover device; 14. Workpiece exchange device. DETAILED DESCRIPTION

[0037] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific embodiments. However, the following embodiments are only preferred embodiments of the present invention, not all of them. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without making any creative work shall fall within the scope of protection of the present invention.

[0038] The present invention provides an automated polishing process for a metal soup spoon with a handle. The metal soup spoon comprises a spoon head, a handle precision casting, and a handle. The two ends of the handle precision casting are respectively welded to the handle and the spoon head. Two arc-shaped welds are formed at the connection between the handle precision casting and the spoon head. The spoon head comprises a spoon head concave portion and a spoon head convex portion. The automated polishing process comprises the following steps:

[0039] 1. Cleaning before polishing: Clean the metal spoon to be polished after welding thoroughly (water pressure spray can be used for cleaning in order to remove oil);

[0040] 2. Weld flattening: The weld of the polished metal spoon is flattened by profiling and punching;

[0041] 3. Positioning: Place the metal spoon to be polished on the tooling;

[0042] Fourth: Polishing of the handle: The metal spoon to be polished is grabbed by the manipulator picking device, and the handle is radially polished and brushed to obtain uniform radial lines;

[0043] Five: Spoon head polishing: including the polishing of the concave part of the spoon head and the polishing and brushing of the convex part of the spoon head. The polishing of the concave part of the spoon head includes polishing and brushing the mouth of the spoon head, the connection between the concave part of the spoon head and the handle, and the concave surface of the spoon head in sequence, which are used to remove the welding marks of the mouth and the sharp edges caused by the stamping of the mouth, remove the welding marks between the concave part of the spoon head and the handle, polish the surface of the product to reduce the roughness, and remove the original leather grain on the surface of the concave part of the spoon head, so that the surface of the concave part of the spoon head is a sun grain with a radial center, so that the brushed surface has a uniform grain, which is better than the material. The original surface of the material is beautiful. The polishing of the convex part of the spoon head includes polishing and brushing the connection between the convex part of the spoon head and the handle and the surface of the convex part of the spoon head in sequence, which are respectively used to grind the weld at the connection between the convex part of the spoon head and the handle and grind the overall curved surface of the convex part of the spoon head. The rough polishing texture of the convex part of the spoon head is covered to obtain a sun pattern radiating from the center of the circle on the surface of the convex part of the spoon head and remove residual sand particles on the overall curved surface of the convex part of the spoon head to obtain a lower roughness. The polishing order of the concave part of the spoon head and the convex part of the spoon head can be exchanged.

[0044] 6. Post-polishing cleaning: Use environmentally friendly cleaning agents and pure water combined with ultrasonic waves to clean the surface residue of the product through the cleaning production line;

[0045] By performing continuous rough polishing and fine polishing on the handle and spoon head in sequence, the trouble of repeatedly clamping the soup spoon is avoided, and polishing efficiency is improved. Through the combination of continuous rough polishing and fine polishing, the thin-walled spoon head is avoided from being over-polished, reducing thickness loss, while the handle is under-polished and residual oxide scale is left. The weld pores that were not dealt with in time during the rough polishing stage may expand into visible defects during fine polishing, reducing the scrap rate. At the same time, continuous rough polishing is avoided so that the high heat capacity area (handle) is not stored and transferred to the low heat capacity area (spoon head edge), causing sensitization of stainless steel, and uniform rough polishing is prevented from forming overlapping stress areas at the joint, which may cause micro cracks due to uneven stress release after fine polishing. At the same time, the difference in roughness between curved and flat surfaces is greatly reduced, the appearance of uneven texture is reduced, and surface consistency is guaranteed.

[0046] In step 5, a belt sander with a 15mm wide, 180# grit belt and a belt sander with a 20mm wide, 240# grit belt are used to polish the weld at the connection between the spoon head recess and the handle.

[0047] By setting a 180# sanding belt as the coarse grinding stage, the weld slag, oxide layer and obvious unevenness can be quickly removed from the weld, the height difference of the weld can be leveled, and the workload of subsequent fine grinding can be reduced. The 15mm sanding belt width can penetrate into the narrow gap or corner where the spoon head recess and the handle are connected, avoiding excessive grinding of non-welding areas (such as the spoon head recess and handle) due to the sanding belt being too wide, thereby reducing damage to other parts of the workpiece.

[0048] The 240# abrasive belt is used in the fine grinding stage to eliminate scratches left by rough grinding, improve surface finish, and make the weld transition smoother, close to the surface texture of the workpiece itself. The staged processing avoids the efficiency waste of repeated operation of a single abrasive belt. The 20mm width of the abrasive belt is slightly wider, which can cover a larger area on both sides of the weld during fine grinding, achieving a natural transition between the weld and the concave surface of the spoon head and the connection of the handle, avoiding obvious grinding boundaries or steps, and improving processing efficiency. At the same time, the wide abrasive belt has more even pressure distribution, reducing the risk of local over-grinding.

[0049] 180# (medium-coarse) prioritizes treating welding stress concentration areas to avoid local overheating or belt clogging caused by direct use of fine abrasive belts. 240# (fine) reduces the generation of surface microcracks, especially for ductile materials such as stainless steel, which can reduce the risk of fatigue failure caused by stress concentration. The 180# abrasive belt bears the high wear task during the rough grinding stage, protecting the more expensive fine-grained abrasive belt (240#) to maintain sharpness during the fine grinding stage, comprehensively reducing consumable costs. Staged grinding allows operators to visually or tactilely check the surface condition after rough grinding and dynamically adjust fine grinding parameters (such as pressure and angle) to avoid dimensional deviation caused by excessive grinding at one time, which is especially important for precision tableware. Rough grinding quickly removes major defects and shortens single contact time, while fine grinding uses low-pressure operations to reduce frictional heat. The combination of the two reduces the risk of discoloration of materials such as stainless steel caused by local high temperature and maintains the original color of the metal. Staged treatment ensures that the weld area meets higher hygiene standards (reducing microscopic gaps where microorganisms hide). At the same time, the stepped surface treatment can form a more uniform passivation layer and improve corrosion resistance.

[0050] In step 5, a belt sander with a 20mm wide, 240# grit ring sanding belt, a belt sander with a 20mm wide, 240# grit belt, and a belt sander with a 20mm wide, 240# grit nylon belt are used to polish the concave surface of the spoon head;

[0051] A 20mm wide, 240# grit belt can quickly remove macro defects such as stamping burrs, stretch marks, and oxide films on the concave surface. It also performs preliminary polishing on the concave surface, laying the foundation for subsequent fine processing. The belt has good flexibility and can adapt to the arc curvature of the concave surface through the contact wheel or support device of the belt sander, ensuring uniform force on the entire concave area (especially the edge transition) to avoid insufficient or excessive local polishing.

[0052] The 20mm wide, 240# grit belt (a straight-line belt structure) has a more stable motion trajectory and evenly distributed abrasive, making it suitable for fine grinding. After rough polishing with a loop belt, the belt belt can further eliminate the wear marks and uneven sand grain left by the rough polishing, further reducing the surface roughness (Ra value) of the concave surface, approaching the effect of mirror pretreatment. The linear motion of the belt belt can guide the abrasive to polish in a single direction (such as the long axis direction of the concave surface of the spoon head), forming a uniform grain direction, avoiding the cross wear marks that may be caused by loop belts, and improving surface consistency. In addition, the belt belt has better heat dissipation than loop belts (especially during continuous operation), which can reduce the risk of burns on the workpiece surface or loss of abrasive belts due to frictional heat generation. It is suitable for heat-sensitive metal materials (such as the stainless steel material of this metal soup spoon).

[0053] Finally, a 20mm wide, 240# grit nylon belt (usually a nylon fiber base + bonded abrasive) combines flexibility and cutting power. The 240# grit abrasive particles are embedded in the nylon fibers, forming an elastic grinding layer. This layer can "flexibly cut" the subtle scratches and micro-concavities on the concave surface of the spoon head, further improving the surface finish and even achieving a near-mirror effect. The elastic base of the nylon belt avoids hard impact on the concave edges (such as the connection between the spoon head and the handle), preventing edge curling, thinning, or scratches caused by rigid grinding. It is especially suitable for the concave surface of the spoon head with thin-walled structures. The flexible contact of the nylon belt can slightly round the sharp corners and edges within the concave surface of the spoon head, removing residual micro-burrs and improving the feel and safety of the workpiece.

[0054] A combined polishing solution of loop-type abrasive belts, belt-type abrasive belts, and belt-type nylon belts is adopted. Through the progressive process of "rigid rough polishing - rigid fine polishing - flexible fine polishing", the characteristics of different abrasive belt types are fully utilized. This can not only efficiently process the complex curved surfaces and macro defects of the concave part of the spoon head, but also achieve the ultimate optimization of surface quality through fine polishing. The loop-type abrasive belt is responsible for the high-wear local areas, the belt-type abrasive belt is used to process the low-wear large surfaces, and the nylon belt only requires light maintenance, which extends the life of the three types of abrasive belts by 30%-40% simultaneously and reduces the frequency of belt changes on the production line.

[0055] In step 5, a belt sander with a 15 mm wide, 180# grit belt and a belt sander with a 57 mm wide, 180# grit belt are used to polish the weld at the connection between the spoon head convex portion and the handle portion.

[0056] The 15mm, 180# grit loop abrasive belt can closely fit the corners, grooves, and narrow transition areas of the weld (such as the junction of the spoon head convex part and the handle part). The flexibility of the loop structure allows it to bend with the weld contour, accurately grinding the weld root and the fusion line on both sides, avoiding "edge leakage" or "over-grinding of non-weld areas" caused by the wide abrasive belt due to excessive coverage. The grinding track of the narrow abrasive belt is concentrated on the weld itself, which can reduce accidental grinding of non-weld surfaces of the spoon head convex part (such as the convex arc surface) and protect the accuracy and finish of the processed surface.

[0057] The 57mm 180# grit ring abrasive belt has a large coverage area. Through the high-speed operation of the abrasive belt machine, it can remove macro defects such as weld excess height, weld bead, and spatter in batches, improving the rough polishing efficiency. The large contact area of ​​the wide abrasive belt can evenly distribute the grinding force on the weld surface, avoiding overheating, deformation or uneven thickness of the weld caused by localized grinding with a narrow abrasive belt.

[0058] Among them, the 15mm narrow abrasive belt is responsible for 70% of deep defect removal, and the 57mm wide abrasive belt completes 30% of surface flattening. Although both have the same 180# grit, they achieve a cutting effect equivalent to the "coarse-medium" grit conversion through the difference in contact area. The instantaneous high temperature (about 180℃) of the 15mm narrow abrasive belt utilizes the local thermal softening effect to improve cutting efficiency, and the 57mm wide abrasive belt continuously grinds at a low temperature (<80℃) to achieve stress relief annealing simultaneously. The combined process controls the hardness fluctuation of the heat-affected zone within HRB5, and the grinding at the weld corners has less wear on the abrasive belt. Severe wear and tear can be caused by using a 15mm narrow abrasive belt to replace worn areas locally (without scrapping the entire roll of abrasive belt), reducing consumable costs. The 15mm narrow abrasive belt can accurately grind the root of the weld to remove micro defects such as lack of fusion and undercuts. The 57mm wide abrasive belt can level the weld surface, reduce the risk of stress concentration, and improve the overall bending strength of the soup spoon (especially the connection between the handle and the spoon head, which is a weak point). The uniform grinding of the 57mm wide abrasive belt can prevent the weld thickness from being reduced due to local over-grinding (such as insufficient weld reinforcement), ensuring that the weld load-bearing capacity meets the design requirements.

[0059] Both abrasive belts use 180# grit (medium roughness), which creates a consistent grinding pattern on the weld surface, avoiding the mottled appearance caused by differences in abrasive belt grit. After grinding, the weld is aligned with the grain of the spoon head and handle, enhancing the aesthetics of the product. After combined grinding, the flatness and roughness of the weld surface meet the requirements for fine polishing, eliminating the need for repeated rough polishing and shortening the overall processing cycle.

[0060] The polishing solution adopts a combination of narrow (15mm) and wide (57mm) ring-type abrasive belts of the same grit size. Through the synergistic effect of "precise local processing + efficient large-area leveling", it not only solves the grinding problem of complex weld areas, but also ensures the efficiency of mass production.

[0061] In step 5, a belt sander with a 57mm wide 180# grit belt, a belt sander with a 57mm wide 240# grit belt, a belt sander with a 20mm wide 240# grit belt, and a belt sander with a 20mm wide 240# grit nylon belt are used to polish the convex surface of the spoon head.

[0062] The 57mm wide 180# coarse-grained abrasive belt is used. The larger abrasive grains of the 180# coarse-grained abrasive belt are suitable for removing large-area defects such as stamping burrs, oxide scale, and surface scratches on convex surfaces. The 57mm wide design allows the high-speed reciprocating motion of the abrasive belt machine to quickly level the unevenness of the convex surface of the spoon head (such as local bumps during stamping), improving rough polishing efficiency. The annular structure of the coiled abrasive belt has a certain degree of elasticity and can slightly deform with the arc curvature of the convex and concave surface of the spoon head, evenly fitting the curved surface and avoiding "local over-grinding" or "grinding blind spots" caused by curvature mismatch of rigid grinding tools (such as grinding wheels).

[0063] Furthermore, the 240# grit is finer than the 180# grit and is used to remove the coarse grinding lines left by the 180# abrasive belt and reduce surface roughness. The 57mm wide abrasive belt continues to cover the main area of ​​the convex surface to ensure the overall flatness and line consistency of the curved surface. The surface is refined in advance through semi-finishing polishing, which can reduce the grinding load of the subsequent narrow abrasive belt and avoid the time-consuming fine polishing caused by excessively deep coarse grinding lines.

[0064] A 20mm wide, 240# grit belt (the belt moves in a straight line, not in a circular pattern) is suitable for narrow areas such as the intersection of the edge of the spoon head's convex surface and the handle. The belt structure's linear motion trajectory is highly controllable, allowing for targeted grinding along the contour of the spoon head's convex surface. For example, this can be used to smooth out sharp corners on the convex edge, create uniform chamfers, and remove tiny steps or residual burrs at the junction of the convex surface and welds. The 20mm narrow belt acts only on the target area, avoiding the already smooth surface of the spoon head's convex body and preventing secondary scratches caused by accidental contact with the wide belt.

[0065] A 20mm wide, 240# grit nylon belt (usually a nylon fiber base bonded with abrasive grains) has far greater elasticity than ordinary abrasive belts, adapting to the subtle undulations of convex curved surfaces. Through a "flexible fit + micro-cutting" effect, it removes the subtle wear marks left by the 240# abrasive belt, further reducing surface roughness. Without changing the geometric shape, it imparts a uniform matte or semi-mirror finish to the convex surface of the spoon head. The nylon belt's flexible contact prevents the rigid abrasive belt from "biting" the convex surface of the spoon head, safely removing microscopic burrs. This is particularly suitable for thin, easily deformed curved structures like the convex surface of a soup spoon, ensuring no visible burrs and a smooth touch after polishing.

[0066] The four-step combined process of "wide-width rough polishing - wide-width semi-finishing polishing - narrow-width fine polishing - nylon belt finishing" essentially achieves full-process control of "large-area defect removal - curved surface leveling - detail modification - surface brightening" on the convex surface of the soup spoon through differentiated configuration of the abrasive belt width, particle size, and material. This process not only solves the difficult problem of "strengthening both efficiency and precision" in arc surface polishing, but also balances processing quality and product structural safety through the combination of flexible polishing (nylon belt) and rigid polishing (sand belt). For metal tableware such as soup spoons, this solution can simultaneously meet the triple goals of mechanical properties, appearance texture, and production efficiency.

[0067] In step 5, a belt sander with a 20mm wide, 180# grit ring sand belt is used to polish the mouth of the spoon head. 180# is a medium to coarse sand belt with large abrasive particles, which is suitable for quickly removing burrs, flash, oxide scale or rough edges left after stamping or bending, especially the sharp corners or uneven areas that may exist on the mouth of the spoon head after stamping. Compared with coarser grit (such as 80# and 120#), 180# sand belt can remove defects while avoiding excessive grinding that may cause thinning or deformation of the spoon head mouth. Compared with finer grit (such as 240# and 320#), it can complete basic grinding faster in the pretreatment stage, laying the foundation for subsequent fine polishing.

[0068] The mouth of a spoon head is usually curved or has a narrow edge. A 20mm narrow abrasive belt can flexibly penetrate into narrow areas and closely fit the curved shape of the mouth, avoiding the loss of control of the grinding range (such as grinding into adjacent concave or convex surfaces of the spoon head) caused by the abrasive belt being too wide. The 20mm narrow abrasive belt is easier to control during operation and is particularly suitable for straight or circular grinding along the edge of the mouth, which can reduce accidental grinding of non-target areas and improve grinding accuracy.

[0069] By grinding away burrs and sharp edges on the mouth, the risk of cracking due to stress concentration during use of the soup spoon can be reduced, while also improving the safety of the user when holding or using it (such as avoiding scratches on the hands).

[0070] The surface roughness of the handle, concave portion of the spoon head, and convex portion of the spoon head are all controlled within Ra0.8um, which is considered fine polishing (the general polishing target for brushed surfaces is Ra0.2-0.8μm). The surface micro-undulations are extremely small, and light is evenly reflected, giving the soup spoon a soft metallic luster or mirror effect. The roughness is also controlled within Ra0.8um, and the touch is smooth and delicate, avoiding friction discomfort (such as hand abrasion, sweating, and adhesion) when held for long periods of time. The smooth surface of the concave portion of the spoon head (liquid holding surface) can reduce liquid residue and wall sticking, making pouring soup smoother and easier to rinse, making it especially suitable for high-end tableware or children's tableware.

[0071] The microscopic pits on the rough surface easily harbor dirt and become dead corners for bacteria to grow or liquid to remain. The smooth surface with Ra0.8μm can significantly reduce the risk of crevice corrosion and microbial attachment, and meets the hygiene standards for food contact materials.

[0072] like Figure 1 As shown, it also includes several polishing devices 110. The manipulator material picking device 11 is a spoon head adsorption and rotation device. A first turnover device 12, a workpiece exchange device 14, and a second turnover device 13 are sequentially arranged between two adjacent spoon head adsorption and rotation devices. The first turnover device 12 is provided with a first turnover station, which circulates between the two adjacent spoon head adsorption and rotation devices. The first turnover station adsorbs the convex or concave surface of the spoon head. The second turnover device 13 is provided with a second turnover station, which circulates between the two adjacent spoon head adsorption and rotation devices. The second turnover station adsorbs the concave or convex surface of the spoon head. The workpiece exchange device 14 is used to exchange the spoon head close to the first turnover device 12 to the side close to the second turnover device 13, and exchange the direction of the concave surface of the spoon head. The spoon head adsorption and rotation device is used to adsorb or place the spoon head from the first turnover device 12, the workpiece exchange device 14, and the second turnover device 13, and can drive the spoon head to the polishing device 110 for self-rotation polishing;

[0073] Specifically, the specific structures and working principles of the above-mentioned polishing device 110, the manipulator material picking device 11, the first turnover device 12, the workpiece exchange device 14 and the second turnover device 13 have been recorded in a new soup spoon polishing system with the announcement number CN222308445U, and will not be repeated here.

[0074] In step 4, the spoon head adsorption and rotation device adsorbs and drives the metal soup spoon to the nylon wheel polishing machine, starts the nylon wheel motor to rotate the nylon wheel at 300 rpm, and the spoon head adsorption and rotation device rotates in the radial direction of the handle, contacts the nylon wheel, and performs progressive radial surface drawing;

[0075] Nylon wheels have a certain degree of elasticity. Compared with metal grinding wheels or hard abrasive belts, they can buffer mechanical stress during radial rotation and prevent deformation, scratches, or discoloration of the handle (especially thin-walled or welded areas) caused by rigid friction.

[0076] Progressive contact design (e.g., gradually increasing pressure through a cylinder) allows for rough drawing with light pressure first, followed by fine finishing with gradually heavier pressure, thereby removing traces of previous processes (e.g., residual lines after polishing) in stages and improving processing efficiency.

[0077] The radial rotation motion makes all parts of the handle evenly stressed, avoiding work hardening or stress concentration caused by local excessive grinding. The flexible contact of the nylon wheel can also reduce the material annealing caused by frictional heat generation (such as the risk of intergranular corrosion of stainless steel), protecting the original mechanical properties of the material.

[0078] In step 2: the molds required for flattening the weld seam include:

[0079] Lower template 2;

[0080] Support member 5, support member 5 is fixed on the lower template 2, the size of the top surface of the support member 5 is larger than the size of the handle precision casting, and the top surface of the support member 5 is provided with a profiling of the handle precision casting;

[0081] The punch 4 has a notch 41 on one end thereof facing the support member 5;

[0082] The pressing block 42 is fixed in the notch 41 and is located directly above the support member 5;

[0083] When the mold is closed, the two arc-shaped welds abut against the pressing block 42 and the support member 5 respectively;

[0084] After the two ends of the handle precision casting are respectively welded to the handle and the spoon head, the connection between the handle precision casting and the spoon head is placed on the support 5, and at this time the punch 4 is facing an arc weld at the connection between the handle precision casting and the spoon head. By adjusting the punch 4 to move closer to the support 5 until the pressure block 42 contacts the arc weld, the two arc welds are squeezed respectively by the support 5 and the pressure block 42. The pressure helps to correct the local slight misalignment caused by the thermal shrinkage of welding, so that the two sides of the arc weld tend to be flush. The subsequent grinding only requires a very small amount of cutting to achieve a perfect smooth transition, avoiding the subsequent handle precision casting caused by excessive grinding. The casting and spoon head are thinned, and the pressure applied at the same time helps to refine the grains, promote the densification of the microstructure, and close tiny pores or looseness. After the arc weld is compacted, its internal defects are greatly reduced, the density is significantly improved, and it is no longer easy to show "black seams" caused by internal defects or looseness. At the same time, the flattening process also helps to remove part of the surface oxide scale, significantly reducing the raised foreign matter (splash) and superficial defects on the surface. During subsequent grinding, the surface is more uniform and less likely to produce pits or bumps caused by spatter or defects, thereby avoiding these parts from becoming the source of dirt and dirt that appear as "black spots".

[0085] like Figure 4 As shown, the support member 5 is detachably fixed to the side wall of the lower template 2, and the side wall of the lower template 2 is detachably fixed with a support block 6 for supporting the spoon head. The support block 6 can position and support the spoon head, thereby facilitating the quick placement of the soup spoon. Here, the support member 5 and the support block 6 can be locked and fixed to the lower template 2 by screws, making it convenient to disassemble, inspect or replace the support member 5 and the support block 6.

[0086] like Figure 4As shown, two positioning posts 7 are provided on the top surface of the lower template 2. The gap between the two positioning posts 7 is adapted to the width of the handle. By providing two positioning posts 7, the soup spoon can be further quickly positioned, and the handle is stuck between the two positioning posts 7 to ensure that it will not shake, thereby ensuring the stable operation of the pressure welding seam.

[0087] like Figure 2-Figure 4 As shown, it also includes a lower die base 1, an upper die base 3, a pad 8 and a guide column 9. The upper die base 3 can be driven by a cylinder to move closer to or away from the lower die base 1 (the cylinder is not drawn in the figure. This is relative to the existing technology and will not be described here). A movable hole adapted to the guide column 9 is provided on the top surface of the pad 8. The lower template 2 and the pad 8 are both fixed to the surface of the lower die base 1 facing the upper die base 3. The punch 4 and the guide column 9 are both fixed to the surface of the upper die base 3 facing the lower die base 1. The clamping mechanism 10 is fixed on the side wall of the pad 8. By setting the guide column 9 and the pad 8, a guiding role is played, so that the punch 4 can move stably closer to or away from the support 5.

[0088] like Figure 2 、 Figure 4 and Figure 5 As shown, it also includes a clamping mechanism 10 for fixing the spoon head on the support block 6. Specifically, the clamping mechanism 10 includes a first support plate 101, a first connecting rod 102, a second connecting rod 103, a third connecting rod 104 and a fixing block 105. The first support plate 101 is detachably fixed to the side wall of the cushion block 8. The first connecting rod 102 and the third connecting rod 104 are respectively hinged to the first support plate 101. The two ends of the second connecting rod 103 are respectively hinged to the first connecting rod 102 and the third connecting rod 104. When the two hinge points of the second connecting rod 103, the first connecting rod 102 and the third connecting rod 104 and the hinge point of the third connecting rod 104 and the first support plate 101 are in a straight line (as shown in FIG. Figure 4 As shown in the figure, the clamping mechanism 10 is in a locked and fixed state, and the mechanism is at a dead point position. At this time, no matter how large the reaction force (except the destructive reaction force) of the clamped workpiece is, it cannot loosen the fixing block 105. This is the dead point clamping principle in mechanical mechanics. The specific operating principle of this type of clamping mechanism 10 will not be repeated here.

[0089] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An automated polishing process for a metal soup spoon with a handle, characterized in that: The metal soup spoon comprises a spoon head, a handle head precision casting and a handle part, the two ends of the handle head precision casting are respectively welded and fixed to the handle part and the spoon head, the connection between the handle head precision casting and the spoon head has two arc-shaped welds, the spoon head comprises a spoon head concave part and a spoon head convex part, the automatic polishing process The following steps are involved:

1. Cleaning before polishing: Clean the metal spoon to be polished after welding thoroughly; 2. Weld flattening: The weld of the polished metal spoon is flattened by profiling. The molds required for weld flattening include: Lower template (2); A support member (5), the support member (5) being fixed to the lower template (2), the size of the top surface of the support member (5) being larger than the size of the precision casting of the handle, and the top surface of the support member (5) being provided with a shape imitating the precision casting of the handle; A punch (4), wherein the punch (4) is provided with a notch (41) at one end facing the support member (5); A pressing block (42), wherein the pressing block (42) is fixed in the notch (41), and the pressing block (42) is located directly above the support member (5); When the mold is closed, the two arc-shaped welds respectively abut against the pressing block (42) and the support member (5); 3. Positioning: Place the metal spoon to be polished on the tooling; Fourth: Polishing of the handle: The metal spoon to be polished is grabbed by the manipulator picking device, and the handle is radially polished and brushed to obtain uniform radial lines; Five: Spoon head polishing: including the polishing and brushing of the concave part of the spoon head and the convex part of the spoon head. The polishing of the concave part of the spoon head includes polishing and brushing the spoon head mouth, the connection between the concave part of the spoon head and the handle, and the surface of the concave part of the spoon head in sequence. The polishing of the convex part of the spoon head includes polishing and brushing the connection between the convex part of the spoon head and the handle, and the surface of the convex part of the spoon head in sequence.

6. Post-polishing cleaning: Use environmentally friendly cleaning agents and pure water combined with ultrasonic waves to clean the surface residue of the product through the cleaning production line.

2. The automated polishing process for a metal soup spoon with a handle according to claim 1, characterized in that: In step five, a belt sander with a 15 mm wide, 180# grit belt and a belt sander with a 20 mm wide, 240# grit belt are used to polish the weld at the connection between the spoon head recess and the handle.

3. The automated polishing process for a metal soup spoon with a handle according to claim 1, characterized in that: In step five, a belt sander with a 20mm wide, 240# grit ring sanding belt, a belt sander with a 20mm wide, 240# grit belt, and a belt sander with a 20mm wide, 240# grit nylon belt are used to polish the concave surface of the spoon head.

4. The automated polishing process for a metal soup spoon with a handle according to claim 1, characterized in that: In step 5, a belt sander with a 15 mm wide, 180# grit belt and a belt sander with a 57 mm wide, 180# grit belt are used to polish the weld at the connection between the spoon head convex portion and the handle portion.

5. The automated polishing process for a metal soup spoon with a handle according to claim 1, characterized in that: In step 5, a belt sander with a 57mm wide, 180# grit belt, a belt sander with a 57mm wide, 240# grit belt, and a belt sander with a 20mm wide, 180# grit belt were used. Polish the convex surface of the spoon head with a 240# belt sander and a 20mm wide nylon belt sander with a grit size of 240#.

6. The automated polishing process for a metal soup spoon with a handle according to claim 1, characterized in that: In step 5, use a belt sander with a 20mm wide, 180# grit ring belt to polish the spoon head.

7. The automated polishing process for a metal soup spoon with a handle according to claim 1, characterized in that: The surface roughness of the handle, the concave portion of the spoon head and the convex portion of the spoon head are all controlled within Ra0.8um.

8. The automated polishing process for a metal soup spoon with a handle according to claim 1, characterized in that: It also includes a plurality of polishing devices (110), the manipulator material picking device is a spoon head adsorption and rotation device, and a first turnover device (12), a workpiece exchange device (14), and a second turnover device (13) are sequentially provided between two adjacent spoon head adsorption and rotation devices. The first turnover device (12) is provided with a first turnover station, and the first turnover station flows between the two adjacent spoon head adsorption and rotation devices. The first turnover station adsorbs the convex or concave surface of the spoon head. The second turnover device (13) is provided with a second turnover station, and the second turnover station flows between the two adjacent spoon head adsorption and rotation devices. The second turnover station adsorbs the concave or convex surface of the spoon head. The workpiece exchange device (14) is used to exchange the spoon head close to the first turnover device (12) to the side close to the second turnover device (13), and exchange the direction of the concave surface of the spoon head. The spoon head adsorption and rotation device is used to adsorb or place the spoon head from the first turnover device (12), the workpiece exchange device (14), and the second turnover device (13), and can drive the spoon head to the polishing device (110). Self-rotation polishing.

9. The automated polishing process for a metal soup spoon with a handle according to claim 8, characterized in that: In step 4: the spoon head adsorption rotating device adsorbs and drives the metal soup spoon to the nylon wheel polishing machine position, starts the nylon wheel motor to rotate the nylon wheel at 300 rpm, and the spoon head adsorption rotating device rotates radially with the handle, contacts with the nylon wheel for progressive radial surface drawing.

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