Automatic polishing process for metal soup ladle with handle

Abstract

The invention discloses an automatic polishing process for a metal ladle with a handle, and relates to the technical field of polishing, according to the automatic polishing process for the metal ladle with the handle, a manipulator clamps a product to sequentially and continuously carry out rough polishing and fine polishing on a handle part and a ladle head part, the trouble of repeatedly clamping the ladle is avoided, and the polishing efficiency is improved. Through the combination of continuous rough polishing and fine polishing, excessive polishing of the thin-wall spoon head is avoided, thickness loss is reduced, insufficient polishing of the handle is avoided, oxide skin remains, welding bead air holes which are not treated in time in the rough polishing stage are prevented from being possibly expanded into visible defects in the fine polishing process, the rejection rate is reduced, and meanwhile it is avoided that heat is stored in a high-heat-capacity area (handle) and conducted to a low-heat-capacity area (the edge of the spoon head) through continuous rough polishing; the method has the advantages that the surface roughness of the stainless steel is reduced, stainless steel sensitization is triggered, the situation that an overlapped stress area is formed at the joint through unified rough polishing and microcracks are possibly caused by uneven stress release after fine polishing is prevented, meanwhile, the roughness difference between the curved surface and the plane is greatly reduced, uneven lines are reduced, and the surface consistency is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of polishing technology, and particularly to an automated polishing process for a metal soup spoon with a handle. Background Art

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

[0003] There is a prior Chinese invention patent published on January 10, 2025, with the publication number CN119017030B, which discloses an automatic production process for a metal soup spoon. This process solves problems such as the weak strength of the flat handle, easy deformation during transportation and use, manual holding for stretching, low work efficiency, potential safety hazards, the head and handle of the spoon being integrally punched from a stainless steel plate, easy breakage during the process of bending the connection between the handle and the spoon head into a certain arc, weak strength at the bent connection, easy breakage during use, and only being able to perform shallow stretching on the head of the spoon and unable to make a deeper hemispherical spoon head.

[0004] After producing a semi-finished soup spoon through the above production process, it is necessary to polish and grind it. As shown in a Chinese utility model patent published on April 6, 2018, with the publication number CN207189452U, a stainless steel soup spoon grinding system disclosed in the patent, through the structural cooperation of a visual monitoring component with a feeding conveyor belt, a discharging conveyor belt, a spoon handle processing floating component, a soup spoon rough processing floating component, a soup spoon fine processing floating component, a main grasping robot, and a shunting grasping robot, it can automatically realize processes such as workpiece feeding, spoon handle grinding and wire drawing of the workpiece, rough grinding of the upper half of the soup spoon of the workpiece, rough grinding of the lower half of the soup spoon, rough grinding of the inside of the soup spoon, fine grinding of the upper half of the soup spoon of the workpiece, fine grinding of the lower half of the soup spoon, fine grinding of the inside of the soup spoon, and workpiece discharging, with intelligent operation, high efficiency, reduced safety hazards, and improved product processing quality.

[0005] There are the following problems with this polishing method that first performs rough grinding uniformly and then fine grinding: (1) The spoon needs to be clamped repeatedly, resulting in low polishing efficiency; (2) It is difficult to adapt the uniform rough polishing parameters to the characteristics of multiple regions, leading to over-polishing of the thin-walled spoon head (thickness loss > 5%), while the handle is under-polished (residual oxide scale), and the weld porosity that was not handled in time during the rough polishing stage may expand into visible defects (diameter > 0.2 mm) during fine polishing, increasing the scrap rate by 3% - 5%; (3) Continuous rough polishing causes the heat storage in the high heat capacity area (handle) to conduct to the low heat capacity area (spoon head edge), and the local temperature can reach above 150°C, triggering stainless steel sensitization (carbide precipitation). Uniform rough polishing forms an overlapping stress area (-250 MPa) at the connection, and after fine polishing, microcracks (depth > 10 μm) may occur due to uneven stress release; (4) The surface roughness difference between the curved surface and the plane is ±30%, making it easy to have uneven patterns and poor surface consistency. Summary of the Invention

[0006] In order to overcome the deficiencies of the prior art, the present invention provides an automated polishing process for a metal spoon with a handle to solve the problems of low polishing efficiency, over-polishing of the thin-walled spoon head while the handle is under-polished, increased scrap rate, resulting in 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 spoon with a handle, the metal spoon includes a spoon head part, 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 part. There are two arc-shaped welds at the connection between the handle head precision casting and the spoon head part. The spoon head part includes a spoon head concave part and a spoon head convex part. The automated polishing process includes the following steps: One: Cleaning before polishing: Thoroughly clean the metal spoon to be polished after welding. Two: Flattening the weld: Perform profiling stamping and flattening on the weld at the welded part of the metal spoon to be polished. Three: Positioning: Place the metal spoon to be polished on the fixture. Four: Polishing the handle part: Use a manipulator feeding device to grab the metal spoon to be polished and perform radial polishing and wire drawing on the handle part to obtain uniform radial patterns. Five: Polishing the spoon head part: It includes polishing and wire drawing of the spoon head concave part and the spoon head convex part. The polishing of the spoon head concave part includes sequentially polishing and wire drawing the spoon head opening, the connection between the spoon head concave part and the handle part, and the spoon head concave part surface. The polishing of the spoon head convex part includes sequentially polishing and wire drawing the connection between the spoon head convex part and the handle part and the spoon head convex part surface. Six: Cleaning after polishing: Use an environmentally friendly cleaning agent and pure water combined with ultrasonic waves through a cleaning production line to clean the surface residues of the product.

[0008] Preferably, in step five, a belt sander with a loop belt of 15 mm in width and 180# in grit size and a belt sander with a loop belt of 20 mm in width and 240# in grit size are respectively used to polish and grind the weld at the connection between the concave part of the spoon head and the handle part.

[0009] Preferably, in step five, a belt sander with a loop belt of 20 mm in width and 240# in grit size, a belt sander with a belt of 20 mm in width and 240# in grit size, and a belt sander with a belt of 20 mm in width and 240# in nylon belt are successively used to polish the concave surface of the spoon head.

[0010] Preferably, in step five, a belt sander with a loop belt of 15 mm in width and 180# in grit size and a belt sander with a loop belt of 57 mm in width and 180# in grit size are respectively used to polish and grind the weld at the connection between the convex part of the spoon head and the handle part.

[0011] Preferably, in step five, a belt sander with a loop belt of 57 mm in width and 180# in grit size, a belt sander with a loop belt of 57 mm in width and 240# in grit size, a belt sander with a belt of 20 mm in width and 240# in grit size, and a belt sander with a belt of 20 mm in width and 240# in nylon belt are successively and respectively used to polish the convex surface of the spoon head.

[0012] Preferably, in step five, a belt sander with a loop belt of 20 mm in width and 180# in grit size is used to polish the mouth of the spoon head.

[0013] Preferably, the surface roughness of the handle part, the concave surface of the spoon head, and the convex surface of the spoon head are all controlled within Ra0.8um.

[0014] Preferably, it further includes several polishing devices. The manipulator material taking device is a spoon head adsorption and rotation device. Between two adjacent spoon head adsorption and rotation devices, there are successively arranged a first turnover device, a workpiece exchange device, and a second turnover device. The first turnover device is provided with a first turnover station, and the first turnover station circulates between two adjacent spoon head adsorption and rotation devices. The first turnover station adsorbs the convex surface 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 two adjacent spoon head adsorption and rotation devices. The second turnover station adsorbs the concave surface or convex surface of the spoon head. The workpiece exchange device is used to exchange the spoon head on the side close to the first turnover device to the side close to the second turnover device and exchange the concave surface orientation 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, the workpiece exchange device, and the second turnover device, and can drive the spoon head to rotate and polish by itself at the polishing device.

[0015] Preferably, in step four: the spoon head adsorption and rotation device adsorbs and drives the metal soup spoon to the nylon wheel polishing position, starts the nylon wheel motor to drive the nylon wheel to rotate at 300 revolutions per minute, and the spoon head adsorption and rotation device rotates radially along the handle part and contacts the nylon wheel for progressive radial surface wire drawing.

[0016] Preferably, in step two: the mold required for flattening the weld seam includes: The lower template; 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 head precision casting, and a profiling of the handle head precision casting is provided on the top surface of the support member; The punch has a notch opened at one end facing the support member; The pressing block is fixed in the notch and is located directly above the support member; When the mold is closed, the two arc-shaped weld seams are respectively abutted against the pressing block and the support member.

[0017] Compared with the prior art, the beneficial effects that the present invention can achieve are: By successively performing continuous rough polishing and fine polishing on the handle part and the spoon head part, the present invention avoids the trouble of repeatedly clamping the soup spoon, improves the polishing efficiency. Through the combination of continuous rough and fine polishing, over-polishing of the thin-walled spoon head is avoided, thickness loss is reduced, while under-polishing of the handle and residual oxide skin are also avoided. It also prevents the weld bead pores that are not timely processed in the rough polishing stage from expanding into visible defects during fine polishing, reducing the rejection rate. At the same time, it avoids the heat accumulation in the high heat capacity area (handle) during continuous rough polishing from being conducted to the low heat capacity area (spoon head edge) during continuous rough polishing, causing stainless steel sensitization, and prevents the formation of overlapping stress areas at the joints during unified rough polishing, which may lead to micro-cracks due to uneven stress release after fine polishing. At the same time, it greatly reduces the roughness difference between the curved surface and the plane, reduces the appearance of uneven patterns, and ensures surface consistency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of the polishing device, the manipulator feeding device, the first turnover device, the workpiece exchange device and the second turnover device of the present invention; Figure 2 It is a schematic structural diagram of the mold required for flattening the weld seam of the present invention; Figure 3 It is a schematic structural diagram of the upper die base, the punch, the notch, the pressing block and the guide post of the present invention; Figure 4 It is a schematic structural diagram of the lower die base, the lower template, the support member, the support block, the positioning post, the cushion block and the pressing mechanism of the present invention; Figure 5 It is a schematic structural diagram of the pressing mechanism of the present invention; Figure 6 It is a schematic structural diagram after the assembly of the handle part, the handle head precision casting and the spoon head part of the soup spoon; Wherein: 1. Lower die base; 2. Lower template; 3. Upper die base; 4. Punch; 41. Notch; 42. Pressure block; 5. Support member; 6. Support block; 7. Positioning post; 8. Spacer block; 9. Guide post; 10. Pressing 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 material taking device; 12. First turnover device; 13. Second turnover device; 14. Workpiece exchange device. Specific implementation manner

[0019] In order to make the technical means, creative features, achieved purposes and effects realized by the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments. However, the following embodiments are only the preferred embodiments of the present invention, not all of them. Based on the embodiments in the implementation manner, other embodiments obtained by those skilled in the art without creative efforts all belong to the protection scope of the present invention.

[0020] The present invention provides an automatic polishing process for a metal soup spoon with a handle. The metal soup spoon includes a spoon head part, 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 part. There are two arc welds at the connection between the handle head precision casting and the spoon head part. The spoon head part includes a spoon head concave part and a spoon head convex part. The automatic polishing process includes the following steps: One: Cleaning before polishing: Thoroughly clean the metal soup spoon to be polished after welding (here, in order to remove oil, water pressure spraying can be used for cleaning); Two: Flattening the weld: Perform profiling stamping and flattening on the weld at the welding part of the metal soup spoon to be polished; Three: Positioning: Place the metal soup spoon to be polished on the tooling; Four: Polishing the handle part: Use the manipulator material taking device to grab the metal soup spoon to be polished and perform radial polishing and wire drawing on the handle part to obtain uniform radial lines; V: Polishing of the spoon head: It includes polishing, wire drawing of the concave part and convex part of the spoon head. The polishing of the concave part of the spoon head includes polishing and wire drawing of the mouth of the spoon head, the connection part between the concave part of the spoon head and the handle part, and the surface of the concave part of the spoon head in sequence, which are respectively used to remove the welding marks at the mouth and the sharp edges caused by stamping at the mouth, remove the welding marks between the concave part of the spoon head and the handle part, polish the surface of the product to reduce the roughness, and remove the original skin texture on the surface of the concave part of the spoon head, so as to obtain a radial sun pattern centered on the center of the circle on the surface of the concave part of the spoon head, making the surface wire drawing uniform and the texture more beautiful compared with the original surface of the material. The polishing of the convex part of the spoon head includes polishing and wire drawing of the connection part between the convex part of the spoon head and the handle part, and the surface of the convex part of the spoon head in sequence, which are respectively used to grind the weld at the connection part between the convex part of the spoon head and the handle part and grind the overall curved surface of the convex part of the spoon head, covering the rough polishing texture on the surface of the convex part of the spoon head, so as to obtain a radial sun pattern centered on the center of the circle on the surface of the convex part of the spoon head, remove the residual sand grains on the overall curved surface of the convex part of the spoon head, and obtain a lower roughness. The polishing order of the polishing of the concave part of the spoon head and the convex part of the spoon head can be exchanged; VI: Cleaning after polishing: Use an environmentally friendly cleaning agent and pure water combined with ultrasonic waves to clean the surface residues of the product through a cleaning production line; By continuously performing rough polishing and fine polishing on the handle part and the spoon head in sequence, it avoids the trouble of repeatedly clamping the soup spoon, improves the polishing efficiency. Through the combination of continuous rough and fine polishing, it avoids over-polishing of the thin-walled spoon head, reduces the thickness loss, while preventing under-polishing of the handle and residual oxide skin. It also avoids the situation that the weld pores not timely treated in the rough polishing stage may expand into visible defects during fine polishing, reducing the rejection rate. At the same time, it avoids the heat accumulation in the high heat capacity area (handle) during continuous rough polishing being conducted to the low heat capacity area (spoon head edge) during continuous rough polishing, which may cause sensitization of stainless steel, and prevents the formation of overlapping stress areas at the connection during unified rough polishing, which may lead to microcracks due to uneven stress release after fine polishing. At the same time, it greatly reduces the difference in roughness between the curved surface and the plane, reduces the appearance of uneven texture, and ensures surface consistency.

[0021] In step V, a belt sander with a loop belt of 180# grit and a width of 15 mm and a belt sander with a loop belt of 240# grit and a width of 20 mm are respectively used to polish and grind the weld at the connection part between the concave part of the spoon head and the handle part; By setting a belt of 180# grit as the rough grinding stage, it can quickly remove the welding slag, oxide layer and obvious unevenness at the weld, level the height difference of the weld, and reduce the workload of subsequent fine grinding. The 15 mm belt width can penetrate into the narrow gaps or corner parts at the connection between the concave part of the spoon head and the handle part, avoiding over-grinding of non-welded areas (such as the concave part of the spoon head and the handle part) due to too wide a belt, and reducing damage to other parts of the workpiece; As the fine grinding stage, the 240# abrasive belt focuses on eliminating the scratches left by rough grinding, improving the surface finish, making the weld transition smoother, and approaching the surface texture of the workpiece body. The staged treatment avoids the efficiency waste of repeated operations of a single abrasive belt. The 20mm-wide abrasive belt is slightly wider and 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 handle connection, avoiding obvious grinding boundaries or step effects, improving the processing efficiency. At the same time, the pressure distribution of the wide abrasive belt is more uniform, reducing the risk of local over-grinding; The 180# (medium coarse) first treats the welding stress concentration area to avoid local overheating or abrasive belt clogging caused by directly using a fine abrasive belt. The 240# (fine) then reduces the generation of surface microcracks, especially for ductile materials such as stainless steel, and can reduce the risk of fatigue failure caused by stress concentration. The rough grinding stage is undertaken by the 180# abrasive belt for high wear tasks, protecting the more expensive fine-grained abrasive belt (240#) to maintain sharpness in the fine grinding stage, comprehensively reducing the consumable cost. The staged grinding allows the operator to check the surface state after rough grinding visually or tactilely and dynamically adjust the fine grinding parameters (such as pressure, angle), avoiding dimensional deviations caused by over-grinding too deeply at one time, which is particularly important for precision tableware. The rough grinding quickly removes the main defects and shortens the single contact time. The low-pressure operation in fine grinding reduces frictional heat generation. The combination of the two reduces the risk of discoloration caused by local high temperature for materials such as stainless steel, maintaining the metal's natural color. The staged treatment can ensure that the weld area meets higher hygiene standards (reducing the microscopic gaps for microbial hiding), and at the same time, the stepped surface treatment can form a more uniform passivation layer, improving the corrosion resistance.

[0022] In step five, a belt grinder with a 20mm-wide 240# loop abrasive belt, a belt grinder with a 20mm-wide 240# belt abrasive belt, and a belt grinder with a 20mm-wide 240# belt nylon belt are used in sequence to polish the concave surface of the spoon head; The 20mm-wide 240# loop abrasive belt can quickly remove macroscopic defects such as stamping burrs, stretching marks, and oxide films on the concave surface, and at the same time, preliminarily polish the concave curved surface, laying a foundation for subsequent fine treatment. The flexibility of this loop abrasive belt is good, and it can adapt to the arc curvature of the concave surface through the contact wheel or support device of the belt grinder, ensuring uniform stress on the entire concave surface area (especially at the edge transition), avoiding local under-grinding or over-grinding; The belt-type sanding belt (belt structure running in a straight line) with a width of 20mm and a particle size of 240# has a more stable motion trajectory and uniform distribution of abrasives, which is suitable for fine grinding. After rough polishing with the ring-type sanding belt, the belt-type sanding belt can further eliminate the wear marks and uneven sand grains left by rough polishing, so that the surface roughness (Ra value) of the concave surface is further reduced, close to the mirror pretreatment effect. The linear motion of the belt-type sanding belt can guide the abrasive to grind along a single direction (such as the long axis direction of the concave surface of the spoon head) to form a uniform grain direction, avoid the cross wear marks that may be generated by the ring-type sanding belt, and improve the surface consistency. The heat dissipation of the belt-type sanding belt is better than that of the ring-type sanding belt (especially in continuous operation), which can reduce the risk of burns on the workpiece surface or shedding of the abrasive belt due to frictional heat generation. It is suitable for heat-sensitive metal materials (such as the stainless steel material of this metal soup spoon); Finally, a 20mm wide 240# grit nylon belt (usually nylon fiber base + consolidated abrasive) is used to combine flexibility and cutting force. The 240# grit abrasive particles are embedded in the nylon fiber to form an elastic grinding layer, which can perform "flexible cutting" on the fine scratches and microscopic bumps on the concave surface of the spoon head, further improving the surface finish and even achieving a mirror-like effect. The elastic base of the nylon belt can avoid hard impact on the concave edge (such as the connection between the spoon head and the handle), and prevent edge curling, thinning or scratches caused by rigid grinding. It is especially suitable for the concave surface of the spoon head with a thin-walled structure. The flexible contact of the nylon belt can slightly round the sharp angles and sharp edges in the concave surface of the spoon head, remove residual microscopic burrs, and improve the feel and safety of the workpiece. A combined polishing solution of loop abrasive belts, belt abrasive belts, and belt nylon belts is adopted. Through the progressive process of "rigid rough polishing, rigid fine polishing, and flexible fine polishing", the characteristics of different types of abrasive belts are fully utilized. It 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 abrasive belt is responsible for the high-wear local areas, the belt abrasive belt is used to process the low-wear large surfaces, and the nylon belt only needs light maintenance, which can extend the life of the three types of abrasive belts by 30%-40% simultaneously and reduce the frequency of belt replacement on the production line.

[0023] 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 part and the handle part; The loop sanding belt with a grain size of 180# and a width of 15mm can closely fit the corners, grooves and narrow transition areas of the weld (such as the junction of the convex part of the spoon head and the handle part). The flexibility of the loop structure enables it to bend along the weld contour, precisely grinding the root of the weld and the fusion lines on both sides, avoiding the "edge grinding omission" or "over-grinding of non-weld areas" caused by the excessive coverage of a wide sanding belt. The grinding track of the narrow sanding belt is concentrated on the weld itself, which can reduce the accidental grinding of the non-weld surface of the convex part of the spoon head (such as the convex surface and arc surface), protecting the accuracy and smoothness of the machined surface; The loop sanding belt with a grain size of 180# and a width of 57mm has a large coverage area. Through the high-speed operation of the sanding belt machine, it can batch remove macroscopic defects such as weld reinforcement, weld beads and spatter, improving the rough polishing efficiency. The large-area contact of the wide sanding belt can evenly distribute the grinding force on the weld surface, avoiding overheating, deformation or uneven thickness of the weld caused by local concentrated grinding of the narrow sanding belt; Among them, the 15mm narrow sanding belt undertakes 70% of the removal of deep defects, and the 57mm wide sanding belt completes 30% of the surface leveling. Although both have a grain size of 180#, they achieve a cutting effect equivalent to the conversion of "coarse-medium" grain size through the difference in contact area. The instantaneous high temperature (about 180°C) of the 15mm narrow sanding belt utilizes the local thermal softening effect to improve the cutting efficiency, and the 57mm wide sanding belt with continuous low temperature (<80°C) grinding synchronously realizes stress relief annealing. The combined process controls the hardness fluctuation in the heat-affected zone within HRB5. The grinding at the weld corner wears the sanding belt more severely. Using the 15mm narrow sanding belt, the worn part can be locally replaced (without scrapping the whole roll of sanding belt), reducing the consumable cost. The 15mm narrow sanding belt precisely grinds the root of the weld, removing microscopic defects such as lack of fusion and undercut. The 57mm wide sanding belt levels the weld surface, reducing the risk of stress concentration and improving the overall anti-bending strength of the spoon (especially the connection between the handle part and the spoon head part is the weak point of force). The uniform grinding of the 57mm wide sanding belt can prevent the reduction of the weld thickness caused by local over-grinding (such as insufficient weld reinforcement), ensuring that the load-bearing capacity of the weld meets the design requirements; Both sanding belts use a grain size of 180# (medium roughness), which can form consistent grinding patterns on the weld surface, avoiding the appearance mottling caused by the difference in sanding belt grain size. After grinding, the grain direction of the weld is coordinated with that of the convex part of the spoon head and the handle part, improving the product aesthetics. After combined grinding, the flatness and roughness of the weld surface have met the requirements of fine polishing, eliminating the need for repeated rough polishing and shortening the overall processing cycle; Adopting the polishing scheme of combining narrow-width (15mm) and wide-width (57mm) loop sanding belts of the same grain size, through the synergistic effect of "precise local treatment + efficient large-area leveling", it not only solves the grinding problem in complex weld areas but also ensures the efficiency of batch production.

[0024] 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; Through the 57mm wide 180# coarse-grained abrasive belt, the abrasive grain size of the 180# coarse-grained abrasive belt is larger, which is suitable for removing large-area defects such as stamping burrs, oxide scales, surface scratches, etc. on the convex surface. The 57mm wide design can quickly level the ups and downs of the convex arc surface of the spoon head (such as local bumps during stamping) through the high-speed reciprocating motion of the abrasive belt machine, thereby improving the rough polishing efficiency. The annular structure of the ring-type abrasive belt has a certain elasticity, which can be slightly deformed with the arc curvature of the convex and convex surface of the spoon head, evenly fit the curved surface, and avoid "local over-grinding" or "grinding blind area" caused by the mismatch of curvature of rigid grinding tools (such as grinding wheels); Furthermore, the 240# grit is finer than the 180# grit, and is used to remove the rough grinding lines left by the 180# abrasive belt and reduce the surface roughness. The 57mm wide abrasive belt continues to cover the convex main area to ensure the overall flatness and line consistency of the curved surface. The surface is refined in advance through semi-fine polishing, which can reduce the grinding load of the subsequent narrow abrasive belt and avoid the time-consuming fine polishing due to the excessively deep rough grinding lines. The 20mm wide belt with a grain size of 240# (the belt moves in a straight line, not in a ring shape) is suitable for narrow areas such as the boundary line between the edge of the convex surface of the spoon head and the handle. The linear motion trajectory of the belt structure is highly controllable and can be directional grinding along the contour of the convex surface of the spoon head, such as grinding the sharp angle of the convex edge to form a uniform chamfer, grinding the tiny steps or residual burrs at the junction of the convex surface and the weld. The 20mm narrow belt only acts on the target area, avoiding the smooth surface of the convex body of the spoon head that has been processed, and preventing secondary scratches caused by accidental contact of the wide belt; The 20mm wide 240# nylon belt (usually nylon fiber base + abrasive bonded) has much higher elasticity than ordinary abrasive belts, and can conform to the subtle ups and downs of the convex curved surface. Through the "flexible fit + micro-cutting" effect, the fine wear marks left by the 240# abrasive belt are removed, and the surface roughness is further reduced. Without changing the geometric shape, the convex surface of the spoon head is given a uniform matte or semi-mirror gloss. The flexible contact of the nylon belt can avoid the rigid abrasive belt from "biting" the convex surface of the spoon head, and safely remove microscopic burrs. It is especially suitable for the thin and easily deformed curved surface structure of the convex part of the soup spoon, ensuring that there are no visible burrs after polishing and the touch is smooth; The four-step combined process of "wide-width rough polishing --- wide-width semi-fine polishing --- narrow-width fine polishing --- nylon belt fine polishing" is adopted. In essence, the differentiated configuration of the width, particle size and material of the abrasive belt is used to achieve the full process control of "large-area defect removal --- curved surface leveling --- detail modification --- surface brightening" on the convex surface of the soup spoon. This process not only solves the problem of "efficiency and precision are difficult to achieve at the same time" in arc surface polishing, but also balances the processing quality and product structure safety through the combination of flexible grinding (nylon belt) and rigid grinding (abrasive belt). For metal tableware products such as soup spoons, this solution can simultaneously meet the triple goals of mechanical properties, appearance texture and production efficiency.

[0025] In step 5, a belt sander with a 20mm wide 180# grit belt is used to polish the mouth of the spoon head. 180# is a medium to coarse belt grit with large abrasive particles, which is suitable for quickly removing burrs, flash, oxide scale or rough edges left after stamping or bending, especially the edges and corners or uneven areas that may exist at the mouth of the spoon head after stamping. Compared with coarser grit (such as 80# and 120#), 180# abrasive belt can avoid excessive grinding that causes the thickness of the spoon head to be thinned or the shape to be deformed while removing defects. Compared with finer grit (such as 240# and 320#), it can complete the basic grinding faster in the pretreatment stage, laying the foundation for subsequent fine polishing. The mouth of the spoon head is usually an arc or narrow edge structure. The 20mm narrow width abrasive belt can flexibly penetrate into the narrow area and closely fit the curved shape of the mouth, avoiding the loss of control of the grinding range due to the abrasive belt being too wide (such as grinding to the adjacent concave surface or convex surface of the spoon head). The 20mm narrow abrasive belt is easier to control the direction during operation, especially suitable for straight line or arc grinding along the edge of the mouth, which can reduce the mis-grinding of non-target areas and improve the grinding accuracy; By removing burrs and sharp edges at the mouth through grinding, the risk of cracking due to stress concentration during use of the soup spoon can be reduced, while the safety of the user when holding or using it can be improved (such as avoiding scratches on the hands).

[0026] The surface roughness of the handle, the concave surface of the spoon head and the convex surface of the spoon head are all controlled within Ra0.8um, which belongs to the category of fine polishing (the general brushed surface polishing target is Ra0.2~0.8μm). The surface micro-undulations are very small, and the light reflection is uniform, which can make the soup spoon present a soft metallic luster or mirror effect. The roughness is controlled within Ra0.8um and the touch is smooth and delicate, avoiding the friction discomfort (such as grinding, sweating and adhesion) when holding for a long time. The smooth surface of the concave part of the spoon head (liquid holding surface) can reduce liquid residue and wall hanging phenomenon, making it smoother to pour soup and easier to rinse when cleaning. It is especially suitable for high-end tableware or children's tableware; The microscopic pits on the rough surface are prone to dirt accumulation, becoming dead corners for bacterial growth or liquid residue. A smooth surface with Ra 0.8μm can significantly reduce the risk of crevice corrosion and microbial attachment, meeting the hygiene standards for food contact materials.

[0027] As Figure 1 shown, it also includes several polishing devices 110. The manipulator feeding device 11 is a spoon head adsorption and rotation device. Between adjacent spoon head adsorption and rotation devices, there are successively arranged a first turnover device 12, a workpiece exchange device 14, and a second turnover device 13. The first turnover device 12 is provided with a first turnover station, and the first turnover station circulates between adjacent two 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 circulates between adjacent two 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 on the side close to the first turnover device 12 to the side close to the second turnover device 13 and exchange the concave surface orientation 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 rotate and polish itself at the polishing device 110; Specifically, the specific structures and working principles of the above-mentioned polishing device 110, manipulator feeding device 11, first turnover device 12, workpiece exchange device 14, and second turnover device 13 have been recorded in a new type of spoon polishing system with the publication number CN222308445U, and will not be elaborated here.

[0028] In step four: The spoon head adsorption and rotation device adsorbs and drives the metal spoon to the nylon wheel polishing position, starts the nylon wheel motor to drive the nylon wheel to rotate at 300 revolutions per minute, and the spoon head adsorption and rotation device rotates radially with respect to the handle part, and contacts the nylon wheel for progressive radial surface wire drawing; The nylon wheel itself has a certain elasticity. Compared with a metal grinding wheel or a hard abrasive belt, it can buffer mechanical stress during radial rotation contact, avoiding deformation, scratching, or overheating discoloration of the handle part (especially the thin-wall or welded area) caused by rigid friction; The progressive contact design (such as gradually increasing the pressure through a cylinder) can first perform rough wire drawing with light pressure, and then gradually increase the weight to complete fine repair, removing the traces of the previous process (such as the residual texture after polishing) in stages, improving the processing efficiency; The radial rotation movement makes each part of the handle part evenly stressed, avoiding work hardening or stress concentration caused by local excessive grinding. The flexible contact of the nylon wheel can also reduce 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.

[0029] In step two: The mold required for flattening the weld includes: The lower template 2; A support member 5, which is fixed to the lower template 2. The size of the top surface of the support member 5 is larger than that of the handle head precision casting, and a profiling of the handle head precision casting is provided on the top surface of the support member 5. A punch 4, with a notch 41 formed at one end of the punch 4 facing the support member 5. A pressing block 42, which is fixed in the notch 41 and is located directly above the support member 5. When the mold is closed, the two arc-shaped weld seams are respectively in contact with the pressing block 42 and the support member 5. After the two ends of the handle head precision casting are respectively welded and fixed to the handle part and the spoon head, the connection part between the handle head precision casting and the spoon head is placed on the support member 5. At this time, the punch 4 is facing an arc-shaped weld seam at the connection part between the handle head precision casting and the spoon head. By adjusting the punch 4 to move closer to the support member 5 until the pressing block 42 contacts the arc-shaped weld seam, the two arc-shaped weld seams are respectively extruded by the support member 5 and the pressing block 42. The pressure helps to correct the local minor misalignment caused by welding thermal shrinkage, making the two sides of the arc-shaped weld seam tend to be flush. Only a very small amount of cutting is required for subsequent grinding to achieve a perfect smooth transition, avoiding the thinning of the handle head precision casting and the spoon head caused by excessive grinding in the subsequent process. At the same time, the applied pressure helps to refine the grains, promote the densification of the microstructure, close the tiny pores or looseness. After the arc-shaped weld seam is compacted, the internal defects are significantly reduced, and the density is significantly improved. It is no longer easy to show the "black seam" 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 matters (spatter) and superficial defects on the surface. During subsequent grinding, the surface is more uniform and is not prone to produce pits or bumps caused by spatter or defects, thus avoiding these parts from becoming the source of dirt accumulation and showing as "black dots".

[0030] As Figure 4 shown, the support member 5 is detachably fixed to the side wall of the lower template 2. A support block 6 for supporting the spoon head is detachably fixed to the side wall of the lower template 2. The support block 6 can position and support the spoon head, thus 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, which is convenient for disassembling, inspecting, or replacing the support member 5 and the support block 6.

[0031] As Figure 4 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 part. By setting the two positioning posts 7, the soup spoon can be further quickly positioned, and the handle part is stuck between the two positioning posts 7 to ensure no shaking, thus ensuring the stable progress of the pressure welding seam operation.

[0032] As Figures 2 - 4As shown, it further includes a lower die base 1, an upper die base 3, a spacer block 8 and a guide post 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 shown in the figure. This is relative to the prior art and will not be elaborated here). The top surface of the spacer block 8 is provided with a movable hole adapted to the guide post 9. The lower template 2 and the spacer block 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 post 9 are both fixed to the surface of the upper die base 3 facing the lower die base 1. The pressing mechanism 10 is fixed to the side wall of the spacer block 8. By providing the guide post 9 and the spacer block 8, a guiding effect is achieved, enabling the punch 4 to stably move closer to or away from the support member 5.

[0033] As Figure 2 , Figure 4 and Figure 5 shown, it further includes a pressing mechanism 10 for fixing the spoon head to the support block 6. Specifically, the pressing 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 spacer 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 with the first connecting rod 102 and the third connecting rod 104 and the hinge point of the third connecting rod 104 with the first support plate 101 are on a straight line (as Figure 4 shown), the pressing mechanism 10 is in a locked and fixed state, and the mechanism is at a dead point position. At this time, for the workpiece being pressed, no matter how large the reaction force (except for a destructive reaction force) is, it cannot make the fixing block 105 loosen. This is the dead point clamping principle in mechanical mechanics, and the specific operating principle of such a pressing mechanism 10 will not be elaborated here.

[0034] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present 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 includes 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. There are two arc-shaped weld seams at the connection between the handle head precision casting and the spoon head. The spoon head includes a spoon head concave part and a spoon head convex part. The automated polishing process comprises the following steps: I. Cleaning before polishing: Thoroughly clean the metal soup spoon to be polished after welding; II. Flattening the weld seam: Perform profiling stamping and flattening on the weld seam at the welded part of the metal soup spoon to be polished; III. Positioning: Place the metal soup spoon to be polished on the fixture; IV. Polishing the handle part: Use a manipulator feeding device to grab the metal soup spoon to be polished and perform radial polishing and wire drawing on the handle part to obtain uniform radial patterns; V. Polishing the spoon head: It includes polishing and wire drawing of the spoon head concave part, the spoon head convex part. The polishing of the spoon head concave part includes sequentially polishing and wire drawing the spoon head opening, the connection between the spoon head concave part and the handle part, and the spoon head concave part surface. The polishing of the spoon head convex part includes sequentially polishing and wire drawing the connection between the spoon head convex part and the handle part and the spoon head convex part surface; VI. Cleaning after polishing: Use an environmentally friendly cleaning agent and pure water combined with ultrasonic waves through a cleaning production line to clean the surface residues of the product.

2. The automated polishing process of the metal soup spoon with a handle according to claim 1, characterized in that: In step V, a belt sander with a 15-mm-wide loop belt of 180# grit and a belt sander with a 20-mm-wide loop belt of 240# grit are respectively used to polish and grind the weld seam at the connection between the spoon head concave part and the handle part.

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

4. The automated polishing process of the metal soup spoon with a handle according to claim 1, characterized in that: In step V, a belt sander with a 15-mm-wide loop belt of 180# grit and a belt sander with a 57-mm-wide loop belt of 180# grit are respectively used to polish and grind the weld seam at the connection between the spoon head convex part and the handle part.

5. The automated polishing process of the metal soup spoon with a handle according to claim 1, characterized in that: In step V, a belt sander with a 57-mm-wide loop belt of 180# grit, a belt sander with a 57-mm-wide loop belt of 240# grit, a belt sander with a 20-mm-wide belt of 240# grit, and a belt sander with a 20-mm-wide belt of 240# grit made of nylon are sequentially and respectively used to polish the spoon head convex part surface.

6. The automated polishing process of the metal soup spoon with a handle according to claim 1, characterized in that: In step V, a belt sander with a 20-mm-wide loop belt of 180# grit is used to polish the spoon head opening.

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

8. The automated polishing process of the metal soup spoon with a handle according to claim 1, characterized in that: It further includes a plurality of polishing devices (110). The manipulator loading device 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 two adjacent spoon head adsorption and rotation devices. The first turnover station adsorbs the convex surface or concave surface of the spoon head. The second turnover device (13) is provided with a second turnover station, which circulates between two adjacent spoon head adsorption and rotation devices. The second turnover station adsorbs the concave surface or convex surface of the spoon head. The workpiece exchange device (14) is used to exchange the spoon head on the side close to the first turnover device (12) to the side close to the second turnover device (13) and exchange the concave surface orientation 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 rotate and polish itself at the polishing device (110).

9. The automated polishing process of the metal soup spoon with a handle according to claim 8, characterized in that: In step four: The spoon head adsorption and rotation device adsorbs and drives the metal soup spoon to the nylon wheel polishing position, starts the nylon wheel motor to drive the nylon wheel to rotate at 300 revolutions per minute, and the spoon head adsorption and rotation device rotates radially along the handle part and contacts the nylon wheel for progressive radial surface wire drawing.

10. The automated polishing process of the metal soup spoon with a handle according to claim 1, characterized in that: In step two: The molds required for flattening the weld seams include: Lower template (2); Supporting member (5), the supporting member (5) is fixed on the lower template (2), the size of the top surface of the supporting member (5) is larger than the size of the handle head precision casting, and the top surface of the supporting member (5) is provided with a profile of the handle head precision casting; Punch (4), a notch (41) is formed at one end of the punch (4) facing the supporting member (5); Pressure block (42), the pressure block (42) is fixed in the notch (41), and the pressure block (42) is located directly above the supporting member (5); When the mold is closed, the two arc-shaped weld seams are respectively in contact with the pressure block (42) and the supporting member (5).

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