Manufacturing method for meat grinder blade

Abstract

The invention discloses a manufacturing method for a meat grinder blade. The manufacturing method comprises the following steps that S01, 440C cutter steel powder is selected; s02, an injection mold corresponding to the meat grinder blade is selected, the injection mold comprises a front mold body and a rear mold body, and the front mold body and the rear mold body are heated; s03, the 440C cutter steel powder is fed into an injection molding machine to form a blank; step S04, trimming the blank piece; s05, the blank is placed on the ceramic plate, the ejector pin face of the blank faces upwards, and the sprue face of the blank faces downwards; s06, the blank obtained after workpiece placing is completed is transferred into a vacuum degreasing furnace to be degreased; s07, the blank is transferred into a vacuum sintering furnace to be sintered; s08, the sintered blank is transferred to a flat grinding machine to be subjected to flat grinding; s09, the blank piece obtained after plane grinding is checked, and the blank piece which is checked to be qualified is subjected to magnetic polishing; the concentricity of the shaft hole of the meat grinder blade and the blade body can be improved, and the coaxiality of the assembled meat grinder blade is correspondingly improved.

Description

Technical Field

[0001] This invention relates to the technical field of meat grinder blade preparation, and in particular to a method for manufacturing meat grinder blades. Background Technology

[0002] Meat grinder blades are used for cutting meat products. They are generally manufactured using machining processes (such as milling, grinding, drilling, etc.). However, because meat grinder blades have a circular blade body, a square shaft hole, a limiting groove, and a cutting part, there are unavoidable drawbacks in the machining process.

[0003] During machining, the workpiece requires multiple steps: first, a lathe is used to machine the circular main body, then a milling machine is used to mill the square shaft hole, followed by the use of an end mill to machine the limiting groove, and finally a grinding machine to grind the cutting part. During the process transition, the workpiece needs to be clamped and positioned multiple times. Each clamping will produce positioning errors, making it difficult to ensure the concentricity of the square shaft hole and the circular main body, which can easily lead to eccentricity. The positional deviation between the limiting groove and the shaft hole will also increase. This deviation will cause the clearance between the meat grinder blade and the drive shaft to be too large during assembly, resulting in obvious shaking during rotation. This not only reduces cutting efficiency but also accelerates the wear of the cutting part and shortens its service life. Summary of the Invention

[0004] The purpose of this invention is to provide a manufacturing method for meat grinder blades, which can improve the concentricity of the shaft hole and the blade body of the meat grinder blade, thereby increasing the coaxiality of the assembled meat grinder blade, reducing the amount of shaking when the meat grinder blade rotates and reducing abnormal wear of the cutting part.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A method for manufacturing a meat grinder blade includes the following steps:

[0007] Step S01: Select 440C tool steel powder;

[0008] Step S02: Select the injection mold corresponding to the meat grinder blade. The injection mold includes a front mold and a rear mold. Heat the front mold and the rear mold.

[0009] Step S03: Feed 440C tool steel powder into the injection molding machine to form a preform;

[0010] Step S04: Trim the edges of the blank;

[0011] Step S05: Place the blank on the ceramic plate with the ejector pin facing upwards and the gate facing downwards;

[0012] Step S06: Transfer the completed blank to a vacuum degreasing furnace for degreasing;

[0013] Step S07: Transfer the degreased blank to a vacuum sintering furnace for sintering;

[0014] Step S08: Transfer the sintered blank to a surface grinder for surface grinding;

[0015] Step S09: Inspect the blank after surface grinding, and perform magnetic polishing on the blanks that pass the inspection.

[0016] Based on the above technical solution, the present invention can be improved as follows:

[0017] Furthermore, in step S02, before injection, the injection mold is preheated using a segmented heating method: the front mold is first heated to 80°C and kept at that temperature for 30 minutes, then heated to 112°C and kept at that temperature for 1 hour; the rear mold is first heated to 90°C and kept at that temperature for 30 minutes, then heated to 120°C and kept at that temperature for 1 hour, while the mold temperature is monitored in real time by a mold temperature sensor.

[0018] Further, in step S03, 440C tool steel powder is added to the injection molding machine barrel. The barrel employs a three-stage temperature control: the initial temperature is 162℃-175℃, the middle temperature is 180℃-195℃, and the final temperature is 200℃-220℃, ensuring uniform melting of the feed material. During injection, graded injection pressure control is used: the initial injection pressure is 40-45 MPa, filling 30% of the injection mold cavity; the middle pressure is 50±5 MPa, filling 90% of the injection mold cavity; and the final pressure is 45-50 MPa for pressure holding and shrinkage compensation. The injection speed is controlled at 50-80 mm / s, and the holding time is 15-20 seconds. After molding, the density of the preform is tested to ensure it is greater than or equal to 5.3 g / cm³. 3 .

[0019] Furthermore, in step S04, a pneumatic trimming knife is first used to preliminarily remove obvious sprue marks on the blank; then, 800-1200 grit sandpaper is used to manually polish the burrs on the edge of the blank, while the blade is preliminarily trimmed.

[0020] Furthermore, in step S05, the blanks are evenly arranged on the ceramic plate, with a spacing of 2-3 mm between two adjacent blanks; the ejector pins of the blanks face upwards, and the gates of the blanks face downwards and are attached to the surface of the ceramic plate.

[0021] Furthermore, in step S06, the ultimate vacuum degree of the vacuum degreasing furnace is less than or equal to 1 Pa, and the degreasing process adopts a stepped heating method: first, the furnace temperature is raised to 80℃ and held for 120 min; then the temperature is raised to 125±5℃ and held for 600±30 min, while the oxalic acid flow rate is controlled by a flow meter and maintained at 3±0.5 g / min; after degreasing, the blank is cleaned for 90 min.

[0022] Further, in step S07, the degreased blank, along with the ceramic plate, is transferred to a graphite plate and then fed into a vacuum sintering furnace with an ultimate vacuum of less than or equal to 0.1 Pa. The sintering process employs a segmented heating curve: preheating from room temperature to 600°C at a rate of 5°C / min; heating from 600°C to 1000°C at a rate of 8°C / min to allow the powder particles to begin diffusing; heating from 1000°C to 1320°C at a rate of 3°C / min to ensure sufficient bonding of the powder particles; holding at 1320°C for 180 min, then cooling to 800°C at a rate of 5°C / min, and finally allowing natural cooling to room temperature; after sintering, the product density is tested to ensure it is greater than or equal to 7.60 g / cm³. 3 The hardness is tested using a Rockwell hardness tester to ensure it is greater than or equal to 40 HRC.

[0023] Further, in step S08, the ejector pin surface of the blank is first ground with a grinding wheel of 1000 mesh, a grinding speed of 15 m / s, and a feed rate of 5 μm / pass, until the flatness of the ejector pin surface is less than or equal to 0.05 mm; then the blank is flipped over and the gate surface is ground with the same parameters as the ejector pin surface; after the grinding is completed, the flatness of each blank is checked piece by piece using an electronic height gauge, and blanks with qualified flatness are selected; then the qualified blanks are sent to the demagnetizer.

[0024] Further, in step S09, the blank with qualified flatness is sent into a magnetic polishing machine, a magnetic polishing needle is added into the polishing machine, and the mass ratio of the polishing needle to the blank is controlled at 5:1; the polishing time is: 10 minutes of clockwise rotation polishing and 5 minutes of counterclockwise rotation polishing; after polishing, the blank is cleaned and dried.

[0025] Furthermore, it also includes:

[0026] Step S10: Inspect the polished finished product and remove defective products;

[0027] Step S11: Package the qualified finished products. Each finished product is packaged in a plastic bag and then placed in a blister tray. The blister tray has multiple compartments to accommodate the finished products and to space adjacent finished products apart.

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

[0029] (1) The invention achieves integrated molding of meat grinder blade blanks through powder metallurgy process, which avoids the problem of error accumulation caused by multiple clamping and positioning in traditional machining from the source, so that the concentricity of the shaft hole and the blade body is controlled within 0.05mm, effectively improving the coaxiality of the assembled meat grinder blade and reducing the amount of shaking during rotation, thereby solving the problem of reduced cutting efficiency and abnormal wear caused by structural deviation.

[0030] (2) The shape of the blank after molding is basically consistent with the outline of the finished product. Only a small amount of trimming and flat grinding is required. The material removal rate is reduced from more than 30% in traditional machining to less than 5%. This not only greatly reduces the waste of high-value 440C tool steel powder, but also reduces the overall production cost of a single blade by simplifying the subsequent processing flow, which is conducive to mass production.

[0031] (3) The blank formed by high temperature sintering forms a uniform and dense metal structure. The hardness deviation of different areas of the same meat grinder blade is less than or equal to 2HRC, which eliminates the problem of uneven performance caused by heat-affected zone during machining. The uniformity of the structure effectively improves the overall wear resistance of the meat grinder blade, and the impact load resistance of the cutting part is also significantly enhanced, reducing the chipping rate of the cutting part, extending the service life, and effectively reducing the user's replacement frequency and usage cost. Attached Figure Description

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Figure 1 This is a schematic diagram of the structure of the meat grinder blade manufactured according to the present invention;

[0034] Figure 2 This is a flowchart of the manufacturing method of the meat grinder blade according to the present invention.

[0035] The markings on the attached diagram are: 1. Blade body; 2. Cutting section; 3. Limiting groove; 4. Shaft hole. Detailed Implementation

[0036] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. These descriptions are intended to aid in understanding the present invention but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] See Figure 1This embodiment relates to a method for manufacturing a meat grinder blade. The manufactured meat grinder blade includes a blade body 1 and a cutting part 2. The blade body 1 is a circular blade structure. A limiting groove 3 is provided on one end face of the blade body 1. A shaft hole 4 is provided at the center of the limiting groove 3. The shaft hole 4 is a square hole and axially penetrates the other end face of the blade body 1. The limiting groove 3 is used to limit the drive shaft of the meat grinder to the shaft hole 4 of the blade body 1. The shaft hole 4 is used to cooperate with the drive shaft of the meat grinder. When the drive shaft of the meat grinder makes a selective movement, the rotation of the blade body 1 drives the cutting part 2 to rotate and cut.

[0038] In this embodiment, four cutting sections 2 are provided, and the cutting sections 2 are arranged at equal intervals along the circumference of the main body. The number of cutting sections 2 can be increased or decreased according to actual needs.

[0039] See Figure 2 This embodiment describes a method for manufacturing meat grinder blades, which includes the following steps:

[0040] Step S01: Select 440C tool steel powder with a hardness range of 58-60 HRC (Rockwell hardness).

[0041] Step S02: Select the injection mold corresponding to the meat grinder blade. The injection mold includes a front mold and a rear mold. Heat the front mold to 112°C and heat the rear mold to 120°C.

[0042] Step S03: Feed 440C tool steel powder into the injection molding machine and injection mold the preform at a material temperature of 162℃-220℃ and an injection pressure of 50±10Mpa. The preform density is greater than or equal to 5.3g / cm³. 3 ;

[0043] Step S04: Trim the edges, remove the sprue and burrs from the blank, and ensure that the outer surface of the blank is flat;

[0044] Step S05: Place the blank on a ceramic plate. The ceramic plate is a flat plate. The blanks are arranged in an array on the ceramic plate. The interval between two adjacent blanks is 2-3mm. The ejector pin surface of the blank faces upward and the gate surface of the blank faces downward.

[0045] Step S06: Transfer the completed blank to a vacuum degreasing furnace for degreasing at a temperature of 125℃±5 for 600±30 min. Oxalic acid is introduced at a rate of 3±0.5 g / min. After degreasing, the blank is washed for 90 min. The degreasing rate after degreasing is greater than or equal to 7.4%.

[0046] Step S07: Place the degreased blank on a graphite plate and transfer it to a vacuum sintering furnace for sintering at 1320℃. The density after sintering is greater than or equal to 7.60 g / cm³. 3The hardness after sintering is greater than or equal to 40 HRC;

[0047] Step S08: Separate the sintered and cooled blank from the ceramic plate and transfer it to a flat grinder for flat grinding; during flat grinding, first grind the ejector pin surface of the blank, then flip it over and grind the gate surface of the blank; after flat grinding, the flatness of the blank is less than or equal to 0.05. Use an electronic height gauge to test the flatness of the blank, screen out blanks with qualified flatness and demagnetize them;

[0048] Step S09: Transfer the qualified blanks to the polishing machine and add a magnetic polishing needle to the polishing machine. Polish for 15 minutes. Use polishing liquid to clean the blanks after initial polishing. After cleaning, screen out the defective parts with residual dirt. Put the qualified blanks into the oven for dehydration and drying. The drying time is 6 minutes and the temperature is 125±10℃.

[0049] Step S10: Inspect the polished finished product and remove defective products;

[0050] Step S11: Package the qualified finished products. Each finished product is packaged in a plastic bag and then placed in a blister tray. The blister tray has multiple compartments to accommodate the finished products and to space adjacent finished products apart.

[0051] In step S01 of this embodiment, the powder particle size is screened using a laser particle size analyzer to ensure uniform particle size distribution within the range of 5-20 μm. At the same time, a Rockwell hardness tester is used to test the hardness of the powder-pressed sample to ensure that its hardness is maintained in the range of 58-60 HRC. In addition, the purity of the steel powder is controlled, requiring that the iron content be greater than or equal to 99.5% and the impurity element content (such as sulfur and phosphorus) be less than or equal to 0.02% to avoid impurities affecting subsequent molding and performance.

[0052] Because 440C tool steel powder has excellent wear resistance and toughness, and its hardness range of 58-60HRC can meet the cutting strength and wear resistance requirements of meat grinder blades, effectively extending its service life; at the same time, its uniform particle size distribution and high purity characteristics can avoid injection molding defects (such as bubbles and cracks) caused by powder agglomeration or impurities, which is beneficial to subsequent preform forming and sintering.

[0053] In step S02 of this embodiment, an injection mold is customized according to the three-dimensional design drawings of the meat grinder blade. The injection mold includes a front mold and a rear mold that can form a molding cavity when the mold is closed. Before injection, the injection mold is preheated by a segmented heating method: the front mold is first heated to 80°C and kept at that temperature for 30 minutes, and then heated to 112°C and kept at that temperature for 1 hour; the rear mold is first heated to 90°C and kept at that temperature for 30 minutes, and then heated to 120°C and kept at that temperature for 1 hour. At the same time, the mold temperature is monitored in real time by a mold temperature sensor.

[0054] Due to segmented preheating and precise temperature control, the cavity deformation caused by thermal stress due to excessive temperature difference in the injection mold can be avoided. Moreover, it can ensure that the molten material and the cavity of the injection mold are fully in contact during injection, reducing defects such as shrinkage marks and material shortage on the surface of the blank, and improving the appearance and dimensional accuracy of the blank.

[0055] In step S03 of this embodiment, 440C tool steel powder is added to the injection molding machine barrel. The barrel uses a three-stage temperature control: the first stage temperature is 162℃-175℃, the middle stage is 180℃-195℃, and the last stage is 200℃-220℃ to ensure uniform melting of the feed material. During the injection process, staged injection pressure control is adopted. The initial injection pressure is 40-45 MPa, filling 30% of the injection mold cavity; the middle stage pressure is 50±5 MPa, filling 90% of the injection mold cavity; and the final stage pressure is 45-50 MPa for pressure holding and shrinkage compensation. The injection speed is controlled at 50-80 mm / s, and the holding time is 15-20 s. The density of the molded preform is tested to ensure that it is greater than or equal to 5.3 g / cm³. 3 The molded blank has an ejector pin surface and a gate surface. The ejector pin surface is one end face of the blank that contacts the ejector pin of the injection mold, and the gate surface is the other end face of the blank that connects to the gate of the injection mold.

[0056] Thanks to its three-stage material temperature control and graded injection pressure design, the flow rate and filling process of the molten material can be precisely controlled, avoiding dimensional deviations in the preform caused by sudden pressure changes or uneven material temperature. This ensures that the tolerances of key preform dimensions (such as blade thickness and mounting hole diameter) are less than or equal to ±0.1mm; simultaneously, the density of the molded preform is greater than or equal to 5.3g / cm³. 3 This results in low internal porosity of the blank, which reduces shrinkage and deformation during subsequent degreasing and sintering processes, and avoids cracks after sintering due to the looseness of the blank.

[0057] In step S04 of this embodiment, a combination of manual and mechanical trimming is used. First, a pneumatic trimming knife is used to preliminarily remove the obvious sprue (approximately 10mm in length and 5mm in diameter) on the blank. During the removal, the pneumatic trimming knife is kept at a 45° angle to the surface of the blank to avoid damaging the blank body. Then, sandpaper (800-1200 grit) is used to manually polish the burrs (thickness less than or equal to 0.1mm) on the edge of the blank. During the polishing process, a horizontal reciprocating motion is used, and the force is controlled at 5-10N to ensure the flatness of the outer surface of the blank. At the same time, the blade is preliminarily trimmed to avoid chipping of the cut part 2 during the trimming process.

[0058] Because the trimming process removes excess structures such as sprues and burrs, the surface of the blank is made smooth and flat. This avoids excess material from hindering the penetration of the degreasing agent during subsequent degreasing, or product deformation caused by excess structures during sintering. It also reduces the machining allowance for subsequent flat grinding and polishing processes. At the same time, the combination of pneumatic trimming and manual grinding can efficiently remove excess parts while precisely controlling the force and angle to avoid damaging critical parts such as the blade, thus ensuring the integrity of the blank in subsequent processing.

[0059] In step S05 of this embodiment, an alumina ceramic plate with high temperature resistance (greater than or equal to 1500℃) and high flatness (flatness less than or equal to 0.03mm) is selected. The surface of the ceramic plate is sandblasted (roughness Ra=1.6μm) to enhance the friction between the blank and the ceramic plate and prevent the blank from shifting during transportation. When placing the blanks on the tray, tooling fixtures are used to assist in positioning. The blanks are evenly arranged on the ceramic plate in a 2×3 array to ensure that the interval between two adjacent blanks is controlled at 2-3mm (measured with calipers). At the same time, the placement direction of the blanks is specified: the ejector pin surface of the blank faces upward to facilitate priority processing during subsequent flat grinding, and the gate surface of the blank faces downward to fit against the surface of the ceramic plate to avoid deformation of the gate part due to external force during degreasing and sintering.

[0060] By using spaced-out blanks, each blank can be evenly contacted with the degreasing agent and heat source during subsequent degreasing and sintering processes. This avoids problems such as incomplete degreasing and inconsistent sintering shrinkage caused by blank stacking or uneven spacing, thus improving the batch quality stability of the product. At the same time, the blank placement direction with the ejector pin facing up and the gate facing down is beneficial for subsequent flat grinding processes, reducing the adjustment time between processes. The high flatness of the ceramic plate can prevent the blanks from deforming during placement.

[0061] In step S06 of this embodiment, the finished blanks, along with the ceramic plates, are transferred to a vacuum degreasing furnace with an ultimate vacuum of less than or equal to 1 Pa. The degreasing process employs a stepped heating method: first, the furnace temperature is raised to 80°C and held for 120 min; then, it is raised to 125±5°C and held for 600±30 min, while the oxalic acid flow rate is controlled by a flow meter and maintained at 3±0.5 g / min. After degreasing, the blanks are transferred to an ultrasonic cleaning tank with a frequency of 40 kHz and a power of 500 W. A neutral cleaning agent with a pH of 7-8 is used for cleaning for 90 min to remove residual oxalic acid and decomposition products from the surface of the blanks. Finally, the degreasing rate is tested to ensure that it is greater than or equal to 7.4%.

[0062] The use of stepped heating avoids the formation of pores inside the sintered blank; at the same time, degreasing in a vacuum environment avoids oxidation reaction between oxygen in the air and the blank. The slow heating rate and stable supply of degreasing agent reduce cracking and deformation of the blank, ensuring the structural integrity of the blank after degreasing.

[0063] In step S07 of this embodiment, the degreased blank, along with the ceramic plate, is transferred to a graphite plate and then fed into a vacuum sintering furnace with an ultimate vacuum of less than or equal to 0.1 Pa. The sintering process employs a segmented heating curve: preheating from room temperature to 600°C at a rate of 5°C / min; heating from 600°C to 1000°C at a rate of 8°C / min to allow the powder particles to begin diffusing; heating from 1000°C to 1320°C at a rate of 3°C / min to ensure sufficient bonding of the powder particles; holding at 1320°C for 180 min, then cooling to 800°C at a rate of 5°C / min, and finally allowing natural cooling to room temperature; after sintering, the product density is tested to ensure it is greater than or equal to 7.60 g / cm³. 3 The hardness is tested using a Rockwell hardness tester to ensure it is greater than or equal to 40 HRC.

[0064] By employing high-temperature sintering at 1320℃ and optimizing the heating and cooling curves, the 440C steel powder particles are fully diffused and combined, forming a dense metallic structure with a density greater than or equal to 7.60 g / cm³ and a hardness greater than or equal to 40 HRC. This ensures that the blade has sufficient cutting strength and wear resistance, meeting the long-term high-intensity working requirements of meat grinder blades. At the same time, the vacuum sintering environment effectively isolates air, preventing oxidation of the blank at high temperatures and ensuring the surface quality and internal performance of the product. The slow heating and cooling rates reduce internal thermal stress in the blank, preventing sintering cracks or deformation and improving the product qualification rate.

[0065] In step S08 of this embodiment, the sintered and cooled blank is separated from the ceramic plate. A special pry bar is used for separation to avoid excessive force that could damage the blank. The separated blank is transferred to a surface grinder with a grinding head precision of less than or equal to 0.005 mm. During surface grinding, the ejector pin surface of the blank is first ground with a grinding wheel grit of 1000 mesh, a grinding speed of 15 m / s, and a feed rate of 5 μm / pass until the flatness of the ejector pin surface is less than or equal to 0.05 mm. Then, the blank is flipped over and the gate surface is ground with the same parameters as the ejector pin surface to ensure that the flatness of both ends meets the requirements. After surface grinding, the flatness of each blank is checked piece by piece using an electronic height gauge, and blanks with qualified flatness are selected. Subsequently, qualified blanks are sent to a demagnetizer for demagnetization to remove the magnetism generated during processing and prevent the blanks from adsorbing iron filings that would affect subsequent use.

[0066] Because a demagnetizing process is used to remove the magnetism from the blank, it avoids the adsorption of iron filings during use, which could lead to increased blade wear or contamination of the meat, thus improving the safety and hygiene of the product.

[0067] In step S09 of this embodiment, the blank with qualified flatness is sent into a magnetic polishing machine with a magnetic field strength greater than or equal to 5000 Gs. A special magnetic polishing needle is added into the polishing machine. The polishing needle is made of stainless steel with a diameter of 1-2 mm and a length of 5-8 mm. The mass ratio of the polishing needle to the blank is controlled at 5:1. During the polishing process, the magnetic field drives the polishing needle to move at high speed to finely polish the surface of the blank and the cut part 2, removing scratches left by the flat grinding. The polishing time is set to 15 minutes, specifically: 10 minutes of clockwise rotation polishing, and then counterclockwise rotation polishing. Polish by rotating for 5 minutes; after polishing, transfer the blank to an ultrasonic cleaning tank with a frequency of 60kHz and a power of 800W. Add a special polishing solution with a pH of 6-7 and clean for 20 minutes to remove residual polishing debris and dirt from the surface of the blank. After cleaning, visually inspect and use strong light to screen out defective parts with residual dirt, surface scratches, etc. Place the qualified blanks into a hot air circulating oven, set the drying temperature to 125±10℃, and the drying time to 6 minutes. Control the air speed inside the oven at 1-2m / s to ensure that the surface of the blank dries quickly and avoids rusting.

[0068] Because magnetic polishing avoids creating grinding dead angles, it not only improves the smoothness of the blank surface, but also, by using a combination of polishing liquid cleaning and hot air drying, it can thoroughly remove dirt from the blank surface. The drying process can quickly remove moisture, and with the anti-rust components of the polishing liquid, it can effectively prevent the blank from rusting during subsequent storage and transportation, thus extending the product's shelf life.

[0069] In step S10 of this embodiment, the finished product is visually inspected for defects such as cracks, dents, and rust by strong light irradiation with an intensity greater than or equal to 5000 lux. At the same time, a magnifying glass is used to check whether the cut part 2 has chips or curled edges. A coordinate measuring machine is used with a measurement accuracy of ±0.002mm to sample and inspect the key dimensions of the finished product (such as blade length, thickness, and mounting hole position) at a sampling ratio of 10% to ensure compliance with the design drawings. Unqualified products are then screened out.

[0070] In step S11 of this embodiment, each qualified finished product is packaged in a plastic bag, and the individually packaged finished product is placed in a customized blister tray made of PET. The blister tray has multiple independent compartments according to the size of the finished product. Each compartment is 0.5mm larger than the finished product and has the same depth as the finished product. One finished product is placed in each compartment to ensure that two adjacent finished products are spaced apart to avoid collision and wear during transportation. The blister tray filled with finished products is then placed in a corrugated cardboard box.

[0071] Individual plastic bag packaging can isolate air and moisture, preventing the finished product from rusting; the blister tray cavity design can avoid damage or surface scratches caused by collisions between finished products during transportation, ensuring the finished product arrives in good condition.

[0072] This invention achieves integrated molding of meat grinder blade blanks using powder metallurgy, avoiding the error accumulation problem caused by multiple clamping and positioning in traditional machining. This ensures the concentricity of the shaft hole 4 and the blade body 1 is controlled within 0.05mm, effectively improving the coaxiality of the assembled meat grinder blade and reducing wobble during rotation. This solves the problems of decreased cutting efficiency and abnormal wear caused by structural deviations. The shape of the molded blank is basically consistent with the finished product contour, requiring only minor trimming and surface grinding. The material removal rate is reduced from over 30% in traditional machining to below 5%. This significantly reduces… This process avoids the waste of high-value 440C tool steel powder and reduces the overall production cost of a single blade by simplifying subsequent processing, which is beneficial for mass production. The blank, after high-temperature sintering, forms a uniform and dense metal structure. The hardness deviation of different areas of the same meat grinder blade is less than or equal to 2HRC, eliminating the problem of uneven performance caused by the heat-affected zone during machining. This structural uniformity effectively improves the overall wear resistance of the meat grinder blade, and the impact load resistance of the cutting part 2 is also significantly enhanced, reducing the chipping rate of the cutting part 2, extending its service life, and effectively reducing the user's replacement frequency and operating costs.

[0073] The above embodiments of the present invention are not intended to limit the scope of protection of the present invention. The implementation of the present invention is not limited thereto. All other modifications, substitutions or alterations made to the above structure of the present invention based on the above content of the present invention, in accordance with ordinary technical knowledge and common practice in the field, without departing from the basic technical idea of ​​the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A method for manufacturing a meat grinder blade, characterized in that, Includes the following steps: Step S01: Select 440C tool steel powder; Step S02: Select the injection mold corresponding to the meat grinder blade. The injection mold includes a front mold and a rear mold. Heat the front mold and the rear mold. Step S03: Feed 440C tool steel powder into the injection molding machine to form a preform; Step S04: Trim the edges of the blank; Step S05: Place the blank on the ceramic plate with the ejector pin facing upwards and the gate facing downwards; Step S06: Transfer the completed blank to a vacuum degreasing furnace for degreasing; Step S07: Transfer the degreased blank to a vacuum sintering furnace for sintering; Step S08: Transfer the sintered blank to a surface grinder for surface grinding; Step S09: Inspect the blank after surface grinding, and perform magnetic polishing on the blanks that pass the inspection.

2. The method for manufacturing a meat grinder blade according to claim 1, characterized in that, In step S02, before injection, the injection mold is preheated using a segmented heating method: the front mold is first heated to 80°C and kept at that temperature for 30 minutes, then heated to 112°C and kept at that temperature for 1 hour; the rear mold is first heated to 90°C and kept at that temperature for 30 minutes, then heated to 120°C and kept at that temperature for 1 hour, while the mold temperature is monitored in real time by a mold temperature sensor.

3. The method for manufacturing a meat grinder blade according to claim 2, characterized in that, In step S03, 440C tool steel powder is added to the injection molding machine barrel. The barrel uses a three-stage temperature control: the front section is 162℃-175℃, the middle section is 180℃-195℃, and the rear section is 200℃-220℃ to ensure uniform melting of the feed material. During injection, graded injection pressure control is used: the initial injection pressure is 40-45 MPa, filling 30% of the injection mold cavity; the middle pressure is 50±5 MPa, filling 90% of the injection mold cavity; and the final pressure is 45-50 MPa for pressure holding and shrinkage compensation. The injection speed is controlled at 50-80 mm / s, and the holding time is 15-20 seconds. After molding, the density of the preform is tested to ensure it is greater than or equal to 5.3 g / cm³. 3 .

4. The method for manufacturing a meat grinder blade according to claim 3, characterized in that, In step S04, a pneumatic trimming knife is first used to preliminarily remove obvious sprue marks from the blank; then, 800-1200 grit sandpaper is used to manually polish the burrs on the edge of the blank, while the blade is preliminarily trimmed.

5. The method for manufacturing a meat grinder blade according to claim 4, characterized in that, In step S05, the blanks are evenly arranged on the ceramic plate with a spacing of 2-3 mm between adjacent blanks; the ejector pins of the blanks face upwards and the gates of the blanks face downwards and are attached to the surface of the ceramic plate.

6. The method for manufacturing a meat grinder blade according to claim 5, characterized in that, In step S06, the ultimate vacuum degree of the vacuum degreasing furnace is less than or equal to 1 Pa, and the degreasing process adopts a stepped heating method: first, the furnace temperature is raised to 80℃ and held for 120 min; then the temperature is raised to 125±5℃ and held for 600±30 min, while the oxalic acid flow rate is controlled by a flow meter and maintained at 3±0.5 g / min; after degreasing, the blank is cleaned for 90 min.

7. The method for manufacturing a meat grinder blade according to claim 6, characterized in that, In step S07, the degreased blank, along with the ceramic plate, is transferred to a graphite plate and then placed into a vacuum sintering furnace with an ultimate vacuum of less than or equal to 0.1 Pa. The sintering process employs a segmented heating curve: preheating from room temperature to 600°C at a rate of 5°C / min; heating from 600°C to 1000°C at a rate of 8°C / min to allow powder particle diffusion; heating from 1000°C to 1320°C at a rate of 3°C / min to ensure sufficient powder particle bonding; holding at 1320°C for 180 min, then cooling to 800°C at a rate of 5°C / min, and finally allowing natural cooling to room temperature. After sintering, the product density is tested to ensure it is greater than or equal to 7.60 g / cm³. 3 The hardness is tested using a Rockwell hardness tester to ensure it is greater than or equal to 40 HRC.

8. The method for manufacturing a meat grinder blade according to claim 7, characterized in that, In step S08, the ejector pin surface of the blank is first ground with a 1000-mesh grinding wheel, a grinding speed of 15 m / s, and a feed rate of 5 μm / pass, until the flatness of the ejector pin surface is less than or equal to 0.05 mm. Then, the blank is flipped over and the gate surface is ground with the same parameters as the ejector pin surface. After the grinding is completed, the flatness of each blank is checked piece by piece using an electronic height gauge, and blanks with qualified flatness are selected. The qualified blanks are then sent to the demagnetizer.

9. The method for manufacturing a meat grinder blade according to claim 8, characterized in that, In step S09, the blank with qualified flatness is sent into a magnetic polishing machine, and a magnetic polishing needle is added into the polishing machine. The mass ratio of the polishing needle to the blank is controlled at 5:

1. The polishing time is: 10 minutes of clockwise rotation and 5 minutes of counterclockwise rotation. After polishing, the blank is cleaned and dried.

10. The method for manufacturing a meat grinder blade according to claim 9, characterized in that, Also includes: Step S10: Inspect the polished finished product and remove defective products; Step S11: Package the qualified finished products. Each finished product is packaged in a plastic bag and then placed in a blister tray. The blister tray has multiple compartments to accommodate the finished products and to space adjacent finished products apart.

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