Metal powder injection molding manufacturing process for circular shaver net and circular shaver net

Abstract

The invention provides a circular shaver net metal powder injection molding manufacturing process and a circular shaver net, and the molding process comprises the following steps: S1, preparing a metal powder raw material with the particle size of 0.5-20 [mu] m; s2, a metal powder raw material and a binding agent are mixed and then subjected to injection molding through a metal forming mold, and a knife net blank is obtained; the knife net blank is provided with an inner cavity with a downward opening, and a plurality of pore inlet holes and shaving holes are integrally formed in the net top of the knife net blank; s3, densification of the knife net blank is achieved through gradient degreasing and vacuum sintering; the cutter net blank with the through holes of the hair inlet holes and the through holes of the shaving holes is formed at a time, the process of machining and punching in the later period is not needed, the manufacturing time is shortened, and the manufacturing cost is saved.

Description

Technical Field

[0001] The present invention relates to the field of razor nets, and particularly to a circular razor net and its manufacturing process. Background Art

[0002] The circular net is a common net structure of a rotary razor. Its structure usually has several convex rings around the center at the top of the circular net. The bottom of the convex ring forms a shaving track, and a plurality of hair inlet cutting grooves are formed in the circumferential direction on the convex ring for allowing hair to enter the shaving track for cutting. For the circular net with this structure, after the required shape is formed by stamping a stainless steel sheet, holes or grooves for allowing hair to enter are formed on the convex ring by stamping and punching or grinding wheel cutting; or after being formed by metal powder injection molding, grinding and punching are carried out by a machine tool, and its process is relatively complex, time-consuming, and has a high production cost.

[0003] In view of this, the present application is proposed. Summary of the Invention

[0004] The present invention provides a manufacturing process for a circular net by metal powder injection molding and a circular razor net to solve at least one of the above technical problems.

[0005] To solve the above problems, as one aspect of the present invention, a manufacturing process for a circular net by metal powder injection molding includes:

[0006] S1, preparing a metal powder raw material with a particle size of 0.5 - 20 μm;

[0007] S2, mixing the metal powder raw material and a binder and injecting them through a metal forming die to obtain a net blank;

[0008] The net blank has an inner cavity with an opening facing downward, and a plurality of hair inlet holes and shaving holes are integrally formed on the net top of the net blank;

[0009] S3, realizing densification of the net blank through gradient degreasing and vacuum sintering.

[0010] Preferably, in step S1, the metal powder raw material is a metal powder with a particle size distribution of 1 - 15 μm, and the material of the metal powder is stainless steel, titanium alloy, nickel-based alloy or tungsten steel powder.

[0011] Preferably, in step S2, the metal forming die includes a composite curved surface structure and an annular buffer groove, which are adapted to different facial contours of the net blank.

[0012] Preferably, the metal forming die further includes a main cavity for integrally forming the inlet pores and the shaving pores into through holes. The main cavity is provided with first convex portions uniformly distributed within a circular ring and second convex portions distributed in an annular array. The cross-section of the first convex portion is conical or cylindrical, and the top end is provided with a rounded transition for directly forming the inlet pores into circular through holes. The cross-section of the second convex portion is irregular for directly forming the shaving pores into irregular through holes.

[0013] Preferably, in step S3, the blank of the cutter net is placed in a metal degreasing furnace for degreasing; the degreased blank of the cutter net is placed in a specific metal high-temperature sintering furnace for sintering.

[0014] Preferably, a nitrogen-hydrogen gradient atmosphere is adopted in the sintering stage to inhibit oxidation and improve mechanical properties.

[0015] Preferably, it further includes S4, heat-treating and hardening the blank of the cutter net after high-temperature sintering.

[0016] Preferably, it further includes S5, using chemical mechanical polishing to make the surface roughness Ra of the cutter net ≤ 0.1 μm; depositing a silver ion coating on the inner wall of the mesh holes by physical vapor deposition to inhibit bacterial growth.

[0017] Preferably, in the injection molding process, the injection temperature is 160 - 180 °C; the injection pressure is 80 - 120 MPa, and the holding pressure time is 5 - 10 seconds to avoid separation of the binder due to too high shear rate; the mold temperature is 40 - 60 °C, and the cooling rate is controlled by a circulating water cooling system to reduce residual stress.

[0018] There is also provided a circular cutter net for a shaver, which is made by the above-mentioned circular cutter net metal powder injection molding manufacturing process; it includes a cutter net body, the cutter net body has an inner cavity with an opening facing downward, and inlet pores and shaving pores provided at the top of the cutter net body.

[0019] The present invention realizes the efficient manufacturing of the cutter net for a shaver through the MIM process, has both complex structure, high precision and excellent performance, is applicable to the production of core components of high-end electric shavers, directly integrally forms the inlet pores and the shaving pores, without the need for additional punching, greatly saving production costs and reducing processing time. Description of the Drawings

[0020] Figure 1 is a flowchart of the circular cutter net metal powder injection molding manufacturing process according to an embodiment of the present invention;

[0021] Figure 2 The first perspective structural schematic diagram of the circular cutter net for a shaver according to an embodiment of the present invention;

[0022] Figure 3 is Figure 2Schematic diagram of the second perspective structure

[0023] Reference numerals:

[0024] 1. Knife net body; 11. Inlet pores; 12. Shaving pores Detailed implementation manners

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0026] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention. In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0027] The following will give a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings.

[0028] Please refer to Figures 1 to 2 , a manufacturing process for a circular knife net by metal powder injection molding, including:

[0029] S1. Prepare metal powder raw materials with a particle size of 0.5 - 20 μm;

[0030] S2. Mix the metal powder raw materials and a binder and then inject and mold them through a metal forming mold to obtain a knife net blank;

[0031] The knife net blank has an inner cavity with an opening facing downwards, and a plurality of inlet pores 11 and shaving pores 12 are integrally formed on the net top of the knife net blank;

[0032] S3. Achieve densification of the knife net blank through gradient degreasing and vacuum sintering.

[0033] The circular knife net manufactured by the above MIM metal powder injection molding manufacturing process has a high density, approaching the level of forgings, high precision, suitable for micron-level complex structures, and the hardness can be controlled within HRC 30-45. The MIM process breaks through the material limitations of traditional injection molding processes through a unique path of metal powder + binder injection + sintering densification, achieving the integrated molding of high-precision and high-strength metal parts.

[0034] The circular knife net of this embodiment realizes the efficient manufacturing of the razor knife net through the MIM process, combines complex structures, high precision and excellent performance, is suitable for the production of core components of high-end electric razors, does not require additional punching, greatly saves production costs, and reduces processing time.

[0035] Furthermore, in step S1, the metal powder raw material is metal powder with a particle size distribution of 1-15 μm, and the material of the metal powder is stainless steel, titanium alloy, nickel-based alloy or tungsten steel powder. The density and hardness of the knife net blank formed by the metal powder of this diameter are more suitable for the razor knife net.

[0036] Furthermore, in step S2, the metal forming die includes a composite curved surface structure and an annular buffer groove, which are adapted to different facial contours of the knife net blank. An annular buffer groove is designed around the composite curved surface structure (such as complex curved surfaces, deep cavities or corners), which can effectively disperse the impact force of the molten metal on the die cavity during injection or die casting, reduce local stress concentration, and avoid cracking or deformation of the die caused by repeated high-pressure loading. The annular buffer groove reduces turbulence and gas entrapment phenomena by guiding the flow direction of the molten metal (or metal blank), ensuring uniform filling of the cavity with the material, and is especially suitable for the forming of complex curved surface structures. In addition, the runner design can be optimized by combining finite element analysis to ensure uniform filling of the molten feed and reduce the density gradient (the shrinkage rate is controlled within ±0.3%).

[0037] Furthermore, the metal forming die further includes a main cavity for integrally forming the pore 11 and the shaving hole 12 into through holes. The main cavity can be demolded in cooperation with the parting surface, and the parting surface is arranged in the radial direction of the main cavity. The angle between the parting surface and the horizontal plane can be 3°-8°, so as to adapt to the curved surface demolding of the knife net blank. By adapting the parting surface angle to the curved surface demolding, product deformation can be avoided.

[0038] The main cavity is provided with first convex portions uniformly distributed within a circular ring and second convex portions distributed in a circular array. The cross-section of the first convex portion is conical or cylindrical, and the top is provided with a rounded transition for directly forming the beard inlet holes 11 as circular through-holes. The aperture range of the circular through-holes is 0.3 - 0.8 mm, and they are densely distributed within the circular ring, serving to filter longer beards and only allowing short beards to enter the inside of the cutter net, being cut by the inner blade, directly contacting the skin through the beard inlet holes 11, and preventing the blade from scratching the human body. Further, the beard inlet holes 11 are arranged perpendicular to the top surface of the cutter net body, thereby straightening and fixing the direction of the beards through the tiny holes of the beard inlet holes 11, ensuring that the beards enter the blade cutting area vertically and improving the shaving efficiency.

[0039] The cross-section of the second convex portion is irregular, for directly forming the shaving holes 12 as irregular through-holes. Among them, the cross-section of the second convex portion is a bar-shaped bent irregular through-hole, so as to better match with the inner blade, and can cut various types of beards such as long beards and short and stiff beards, with a faster cutting speed.

[0040] In other embodiments, the cross-section of the second convex portion can be an elongated ellipse, so that the shaving groove forms an elliptical beard inlet groove structure. Both sides of the elliptical beard inlet groove along the radial direction of the cutter net structure are segments of elliptical arcs and the two ellipses have different foci, which can better allow different types of beards to enter the beard inlet groove. When the cutter net of the shaver rotates, it can actively capture the beards and enter the elliptical beard inlet groove.

[0041] Further, the metal forming die can also have a multi-stage demolding structure, which can better demold on the basis of integrally forming the beard inlet holes 11 and the shaving holes 12 into through-holes.

[0042] Further, in step S3, the cutter net blank is placed in a metal degreasing furnace for degreasing; the degreased cutter net blank is placed in a specific metal high-temperature sintering furnace for sintering. Preferably, a two-step degreasing method is adopted. First, solvent degreasing (nitric acid solution, 60 - 80 °C) is used to remove 70% of the binder, and then vacuum thermal degreasing (300 - 500 °C) is used to completely remove the remaining binder.

[0043] The sintering stage adopts a nitrogen → hydrogen gradient atmosphere to inhibit oxidation and improve the mechanical properties. Under a vacuum environment (≤10— 2 Pa), it is heated to 1200 - 1300 °C at a rate of 10 °C / min and held for 2 hours to achieve densification (relative density ≥ 99%).

[0044] Preferably, it further includes S4, and the cutter net blank after high-temperature sintering is heat-treated for hardening.

[0045] Preferably, it further includes S5, and chemical mechanical polishing is adopted to make the surface roughness Ra of the cutter net ≤ 0.1 μm; a silver ion coating is deposited on the inner wall of the mesh hole by physical vapor deposition (PVD) to inhibit the growth of bacteria.

[0046] Preferably, in the injection molding process, the injection temperature is 160 - 180 °C; the injection pressure is 80 - 120 MPa, and the holding pressure time is 5 - 10 seconds to avoid the separation of the binder due to too high shear rate; the mold temperature is 40 - 60 °C, and the cooling rate is controlled by a circulating water cooling system to reduce the residual stress.

[0047] The present application also provides a circular razor cutter net, which is made by the above-mentioned circular cutter net metal powder injection molding manufacturing process; it includes a cutter net body 1, which is obtained after the cutter net blank obtained in step S2 undergoes the processes of step S3 to step S5. The cutter net body 1 has an inner cavity with an opening facing downwards, and a pore 11 for shaving and a shaving hole 12 arranged at the top of the cutter net body 1.

[0048] The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the idea of the present invention belong to the protection scope of the present invention.

Claims

1. A manufacturing process for a circular cutter net by metal powder injection molding, characterized in that, Including: S1. Prepare metal powder raw materials with a particle size of 0.5 - 20 μm; S2. Mix the metal powder raw materials and a binder, and then inject and mold them through a metal forming die to obtain a cutter net blank; The cutter net blank has an inner cavity with an opening facing downwards, and a plurality of inlet pores and shaving pores are integrally formed on the net top of the cutter net blank; S3. Achieve densification of the cutter net blank through gradient degreasing and vacuum sintering.

2. The circular cutter mesh metal powder injection molding manufacturing process according to claim 1, characterized in that In step S1, the metal powder raw materials are metal powders with a particle size distribution of 1 - 15 μm, and the materials of the metal powders are stainless steel, titanium alloy, nickel-based alloy or tungsten steel powders.

3. The manufacturing process of the circular cutter mesh by metal powder injection molding according to claim 1, characterized in that, In step S2, the metal forming die includes a composite curved surface structure and an annular buffer groove, which are adapted to different facial contours of the cutter net blank.

4. The manufacturing process of the circular cutter screen by metal powder injection molding according to claim 3, characterized in that, The metal forming die further includes a main cavity for integrally forming the inlet pores and the shaving pores into through holes. The main cavity is provided with first convex portions evenly distributed within a ring and second convex portions distributed in an annular array; the cross-section of the first convex portion is conical or cylindrical, and the top is provided with a rounded transition for directly forming the inlet pores into circular through holes; the cross-section of the second convex portion is irregular for directly forming the shaving pores into irregular through holes.

5. The manufacturing process of the circular cutter screen by metal powder injection molding according to claim 1, characterized in that In step S3, place the cutter net blank in a metal degreasing furnace for degreasing; place the degreased cutter net blank in a specific metal high-temperature sintering furnace for the sintering process.

6. The circular cutter net metal powder injection molding manufacturing process according to claim 5, characterized in that, During the sintering stage, a nitrogen-hydrogen gradient atmosphere is adopted to inhibit oxidation and improve mechanical properties.

7. The manufacturing process of the circular cutter mesh by metal powder injection molding according to claim 5, characterized in that, It further includes S4. Heat-treat and harden the cutter net blank after high-temperature sintering.

8. The manufacturing process of the circular cutter screen by metal powder injection molding according to claim 7, characterized in that, It further includes S5. Use chemical mechanical polishing to make the surface roughness Ra of the cutter net ≤ 0.1 μm; deposit a silver ion coating on the inner wall of the mesh holes through physical vapor deposition to inhibit bacterial growth.

9. The manufacturing process of the circular cutter screen by metal powder injection molding according to claim 1, characterized in that, In the injection molding process, the injection temperature is 160 - 180 °C; the injection pressure is 80 - 120 MPa, and the holding pressure time is 5 - 10 seconds to avoid separation of the binder due to too high shear rate; the mold temperature is 40 - 60 °C, and the cooling rate is controlled through a circulating water cooling system to reduce residual stress.

10. A circular razor blade net, characterized in that, Made by the manufacturing process of circular cutter net metal powder injection molding according to any one of claims 1 - 9; including a cutter net body, the cutter net body has an inner cavity with an opening facing downwards, and inlet pores and shaving pores provided on the top of the cutter net body.

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