Production process of injection mold

Abstract

The invention discloses a production process of an injection mold, which belongs to the technical field of injection molds, and comprises the following steps: firstly, carrying out demand analysis and mold design through CAD (Computer Aided Design) software to ensure the rationality of a cavity, a runner, a cooling system and an exhaust structure; then die steel or aluminum materials such as P20 and H13 are selected for material preparation; then rough machining is carried out on a preliminary forming module, and the precision of + / -0.01 mm is achieved through CNC, electric spark and other precision machining technologies; then mirror polishing and heat treatment are carried out to improve the surface quality and wear resistance; after assembly debugging is completed, injection molding parameters are optimized through mold testing; and finally carrying out full-size detection and correction by using a three-coordinate measuring instrument to ensure that the mold meets the design standard. According to the production process, the requirements for precision, efficiency and durability are met, and the production efficiency of the injection mold can be improved. Therefore, the production process of the injection mold solves the technical problem of how to improve the production efficiency of the injection mold.

Description

Technical Field

[0001] The present invention relates to the technical field of injection molds, in particular to a production process of injection molds. Background Art

[0002] An injection mold is a specialized tool used in the injection molding process. It primarily consists of a cavity, core, gating system, and ejector mechanism. Molten plastic is injected into a closed mold cavity, where it cools and solidifies to form a plastic product of a specific shape. These molds offer high precision, high efficiency, and repeatable production, making them a core component of mass production for plastic products in industries such as home appliances, automotive, electronics, and medical.

[0003] Based on this, Chinese patent document CN106239835B discloses a method for polishing inserts, which includes the following steps: CNC machining, primary EDM machining, insert coating, secondary EDM machining, wire cutting, and high-precision optical lathe machining. The patent document describes a process for coating the inserts, designing an optimized machining method to ensure coating adhesion strength. A rotary fixture for the inserts is designed, and high-precision optical lathe machining is used to achieve a highly polished surface finish on the adhesive surface. This results in an insert with a finish roughness of 8nm, eliminating the need for workpiece polishing. This allows the product to meet high-gloss requirements during the injection molding process, reducing the number of machining steps and improving the quality, precision, and production efficiency of the inserts.

[0004] However, the injection mold production process disclosed in the prior art still has the technical problem of low production efficiency. Specifically, in the prior art, the process of producing injection molds mainly includes four major links: design, processing, assembly and debugging. First, the mold structure design can be completed through CAD / CAE software; then, CNC processing, electric spark, wire cutting and other precision processing technologies are used to manufacture core components such as mold cores and templates, and then the fit accuracy of each component is ensured through bench assembly. Finally, trial mold debugging is carried out to verify the molding quality and production efficiency of the mold. However, the current injection mold production process needs to rely on electric spark, that is, EDM, to realize the processing and molding of curved surfaces, deep grooves and other structures. Although EDM has high processing accuracy, it takes a long time to mold, which is not conducive to improving the overall production efficiency of injection molds. Summary of the Invention

[0005] Based on this, it is necessary to provide a production process for an injection mold in order to address the technical problem of how to improve the production efficiency of the injection mold.

[0006] A production process for an injection mold comprises the following steps: S1: Demand analysis and mold design. Based on the preset product specifications and material properties, the 3D modeling of the injection mold is completed using CAD software. The cavity, runner system, and cooling water channel are designed as required. At the same time, the draft angle and exhaust system are designed. S2: Material preparation, choose mold steel, such as P20, H13 high wear-resistant steel, etc. or aluminum; S3: Rough machining, using a lathe or milling machine to cut the blank and preliminarily form the module and hole slots; S4: Finishing, using at least one of CNC precision machining, EDM, laser machining, and 3D printing; and using high-speed light cutting strategies as well as thermal management and precision control strategies to process the curved surfaces of injection molds; S5: Surface treatment: Grinding and polishing the mold cavity and other structures of the injection mold to a mirror-grade finish, meeting the requirement of Ra ≤ 0.1μm; heat treatment, quenching and tempering to increase the hardness of the injection mold to HRC 48-52; S6: Assembly and debugging: assemble the mold core, slider, ejector and other components, and check the matching accuracy; then adjust the injection molding parameters such as temperature, pressure, cycle, etc. through trial molds to verify the demoulding smoothness and product size; S7: Inspection, use a three-coordinate measuring machine to perform full-size inspection of the injection mold, compare it with the design tolerance and correct the deviation size in turn.

[0007] Specifically, during the rough machining and finishing processes, the balance between the cutting speed and the spindle speed is controlled according to the material properties of the injection mold being processed.

[0008] Specifically, when milling aluminum alloys, the cutting speed is controlled at 2000–7500 m / min when the spindle speed is ≥18,000 rpm; when milling titanium alloys or hardened steel, the cutting speed is reduced to 150–300 m / min when the spindle speed is in the range of 8,000–15,000 rpm.

[0009] Specifically, in the roughing and finishing processes, the feed rate is controlled by the formula F = Fz × Z × S; where Fz is the feed per tooth, expressed in mm / tooth; Z is the number of tool teeth; and S is the spindle speed, expressed in rpm.

[0010] Specifically, for the processing of aluminum alloys, Fz is 0.02–0.1 mm / tooth; while for the processing of titanium alloys or hardened steel, Fz is reduced to 0.05–0.08 mm / tooth.

[0011] Specifically, for thin-walled parts, a combination of small cutting depth, i.e. Ap ≤ 0.5 mm, and high feed, i.e. F ≥ 2500 mm / min, is used.

[0012] Specifically, the depth of cut is controlled in layers during roughing and finishing. For deep cavity machining, the axial depth of cut (Ap) is limited to 0.8 times the tool diameter; for highly rigid workpieces, the depth of cut is increased to 1.2 times the tool diameter. For radial depth of cut (Ae), for finishing, the depth of cut is limited to 10% of the tool diameter; for roughing, the depth of cut is limited to no more than 70% of the tool diameter.

[0013] Specifically, through iterative calculation, under the constraints of cutting force ≤ machine tool rigidity limit and temperature ≤ material critical value, the parameter combination with the highest material removal rate (MRR) is automatically matched according to the preset algorithm.

[0014] Specifically, the specific steps for automatically matching the parameter combination for the highest material removal rate (MRR) according to the preset algorithm are as follows: S11: Initial population generation, randomly generating 100–500 solutions within the parameter feasible region, covering typical roughing / finishing combinations; S12: Fitness evaluation, calling the cutting simulation model to calculate the MRR, cutting force and temperature of each group, and screening the Pareto frontier solution; S13: Genetic operations: a. Selection, using tournament selection to retain the top 20% individuals in terms of fitness; b. Crossover, arithmetic crossover to generate new solutions by weighted averaging of parent parameters; c. Mutation, Gaussian perturbation mutation with a standard deviation of 5%–10% of the parameter range; S14: Termination condition: stop when the change rate of the optimal solution for 10 consecutive generations is less than 1% or the maximum number of iterations is reached.

[0015] In summary, the production process of an injection mold of the present invention first performs demand analysis and mold design through CAD software to ensure the rationality of the cavity, runner, cooling system and exhaust structure; then selects mold steel or aluminum such as P20 and H13 for material preparation; then performs preliminary molding of the module through rough processing, and then adopts precision processing technologies such as CNC and electric spark to achieve ±0.01mm accuracy; then performs mirror polishing and heat treatment to improve surface quality and wear resistance; after completing assembly and debugging, optimizes injection molding parameters through trial mold; finally uses a three-coordinate measuring instrument to perform full-size inspection and correction to ensure that the mold meets the design standards; the production process proposed by the production process of an injection mold of the present invention takes into account the requirements of accuracy, efficiency and durability, and can improve the production efficiency of the injection mold. Therefore, the production process of an injection mold of the present invention solves the technical problem of how to improve the production efficiency of the injection mold. DETAILED DESCRIPTION

[0016] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the specific embodiments of the present invention are described in detail below with reference to specific embodiments. The following description sets forth many specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar modifications without violating the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0017] Specifically, the present invention provides a production process for an injection mold, which includes the following steps: S1: Demand analysis and mold design. According to the preset product specifications, material properties, such as plastic type, and production requirements, the 3D modeling of the injection mold is completed through CAD software. The cavity and runner system are designed as needed to ensure uniform melt filling and cooling water channels to optimize heat dissipation efficiency. At the same time, the demoulding angle is designed. Usually, the demoulding angle needs to be no less than 0.5° to avoid damage to the plastic product. At the same time, the exhaust system of the injection mold is designed to prevent defects such as air holes during the molding of the plastic part. S2: Material preparation, select mold steel, such as P20, H13 high wear-resistant steel, or aluminum, and select the required mold material based on the complexity and life requirements of the product; S3: Rough machining, using lathe / milling machine to cut the blank and preliminarily form the module and hole slot; S4: Finishing, which can be done by at least one of CNC precision machining, EDM, laser machining, and 3D printing. In CNC precision machining, a CNC machine tool processes the cavity and parting surface of the injection mold, and the mold manufacturing accuracy reaches ±0.01mm. EDM is used to process complex geometric shapes or high-hardness areas in the injection mold, such as deep and narrow grooves. S5: Surface treatment: Grinding and polishing the mold cavity and other structures to a mirror-grade finish, meeting the requirement of Ra ≤ 0.1μm, to reduce demolding resistance; heat treatment, quenching and tempering to increase the hardness of the injection mold to HRC 48-52, while also improving the mold's wear resistance; S6: Assembly and debugging: assemble the mold core, slider, ejector and other components, and check the matching accuracy; then adjust the injection molding parameters such as temperature, pressure, cycle, etc. through trial molds to verify the demoulding smoothness and product size; S7: Inspection, use a three-coordinate measuring machine to perform full-size inspection of the injection mold, compare it with the design tolerance and correct the deviation size in turn.

[0018] Specifically, the overall processing cycle of the production process of the injection mold of the present invention is between 4 and 12 weeks. In actual production, the use of electric spark processing to process complex geometric shapes or high hardness areas in the injection mold, such as deep and narrow grooves, consumes more time.

[0019] Furthermore, high-speed milling (HSM) can significantly reduce electrode reliance and improve surface machining efficiency by using ultra-high spindle speeds, typically between 15,000 and 100,000 rpm, and optimizing machining strategies accordingly. The core mechanisms for reducing electrode usage are as follows: 1. Directly process high-hardness materials. HSM can process mold steel with a hardness of HRC 54-64. It can directly mill complex features such as deep grooves and narrow slits that traditionally require EDM, eliminating the electrode manufacturing step. For example, when machining an HRC 54 mold, using a 0.3mm diameter tool for direct root removal can reduce the number of electrodes and EDM time.

[0020] 2. High-precision thin-wall / microstructure processing capabilities, small cutting depth, that is, finishing in the range of 0.02-0.1mm, combined with high dynamic response, can achieve direct molding of injection mold structures with thin walls, that is, wall thickness ≥ 0.1mm, and micro-rounded corners, that is, rounded corners R0.3mm or less, thereby avoiding secondary EDM repairs.

[0021] The key technologies for improving surface machining efficiency are high-speed, light-cutting strategies and thermal management and precision control strategies. Specifically, the high-speed, light-cutting strategy doubles the material removal rate, achieving feed rates 2–5 times that of traditional milling and increasing roughing efficiency by 3–5 times. For example, the processing time for a toy shell mold can be reduced from several days to 1–2 days. Furthermore, precision surfaces can be formed in a single pass, using a small stepover to increase toolpath density by over 50%. Combined with high rotational speeds, surface roughness can reach Ra 0.4–0.8μm, eliminating 60%–100% of manual polishing cycles. The thermal management and precision control strategy dissipates cutting heat through high-speed chips, typically removing over 80% of the heat. The temperature rise of the processed injection mold workpiece is only approximately 3°C, thus reducing dimensional deviations caused by thermal deformation. Dynamic stability ensures that thin-wall thickness errors are controlled within ±0.05mm, meeting precision surface tolerances.

[0022] Furthermore, in the aforementioned step S4, in the finishing process, when using the high-speed milling process, the tool system used is a short cutting length tool and a high concentricity clamp, such as an HSK-E40 clamp; its function is to avoid vibration and ensure the smoothness of the surface; and the cutting parameters are: aluminum: cutting speed 1,200–1,800 m / min, feed 0.05–0.5 mm / r; steel: optimize the cutting depth / feed ratio; its function is to balance efficiency and tool life; further, the tool path is planned as a tight spiral path, its function is to reduce cutting force fluctuations and improve surface quality.

[0023] Furthermore, in a production process of an injection mold of the present invention, in a method of replacing the electric spark process with a high-speed milling process, the production efficiency comparison is shown in Table 1 below: Table 1: Comparison of production efficiency

[0024] Specifically, in a production process of an injection mold of the present invention, the high-speed milling process needs to be combined with a high-rigidity machine tool, such as a linear motor drive and dedicated CAM software. The initial investment is high, but the overall processing cost can be reduced by 20%-30%; moreover, when the spindle processing speed is ≥18,000rpm, the material removal rate is further doubled when processing aluminum and graphite electrodes.

[0025] Furthermore, in a production process of an injection mold of the present invention, the core principles of cutting parameter optimization of the high-speed milling process mainly include three directions: the first is the balance between cutting speed (Vc) and spindle speed (S), the second is the refined control of feed rate (F), and the third is the layered strategy of cutting depth (Ap / Ae).

[0026] Specifically, the material properties can play a key role in balancing cutting speed and spindle speed. For example, when milling aluminum alloys, when the spindle speed is ≥18,000 rpm, the cutting speed should be controlled within 2,000–7,500 m / min to leverage the aluminum alloy's thermal conductivity. When milling titanium alloys or hardened steel, when the spindle speed is between 8,000–15,000 rpm, the cutting speed should be reduced to 150–300 m / min to avoid high-temperature hardening of the titanium alloy or hardened steel.

[0027] Specifically, for refined feed rate control strategies, the feed rate F can be calculated according to Formula 1: F = Fz × Z × S. In Formula 1, Fz is the feed per tooth, and Z is the number of cutter teeth. For example, in the finishing process of aluminum alloys, Fz is 0.02–0.1 mm / tooth. For example, for a φ6 mm 4-flute milling cutter, at S = 20,000 rpm, F ≈ 1600–8000 mm / min. For roughing processes of titanium alloys or hardened steel, Fz is reduced to 0.05–0.08 mm / tooth to prevent tool chipping. For thin-walled workpieces, a combination of a small depth of cut (Ap ≤ 0.5 mm) and a high feed rate (F ≥ 2500 mm / min) can be used to balance efficiency and prevent deformation.

[0028] Specifically, regarding the layered strategy for depth of cut, in the axial depth of cut (Ap), for deep cavity machining: Ap ≤ ‌0.8 times the tool diameter‌, such as a φ10mm tool, its Ap ≤ 8mm; while for highly rigid workpieces, it can be increased to 1.2 times the tool diameter. In the radial depth of cut (Ae), for finishing machining: Ae ≤ 10% of the tool diameter‌ to ensure the surface roughness of the machined injection mold Ra ≤ 0.8μm; for roughing machining, Ae can not exceed 70% of the tool diameter. Furthermore, in a specific embodiment, for aluminum alloy parts in injection molds, the control method of the anti-sticking knife is as follows: the edge blunting radius of the tool cutting edge is controlled between 0.02–0.03 mm to reduce material adhesion; the cooling method is: high-pressure internal cooling (pressure ≥ 70 bar) to force chip removal to achieve the purpose of cooling and preventing melt adhesion; its cutting speed is not less than 2500 m / min to utilize high speed to suppress built-up edge.

[0029] Furthermore, in a specific embodiment, a highly efficient machining method for hardened steel (HRC 50+) components in injection molds is as follows: the tool material is PCBN or ultrafine-grained cemented carbide to achieve wear resistance and impact resistance, the cutting speed is controlled to 120–180 m / min to avoid accelerated wear caused by thermal softening; and the cutting path is spiral feed + constant cutting depth layering to reduce tool load fluctuations.

[0030] Furthermore, in the aforementioned formula, F = Fz × Z × S, where Fz is the feed per tooth (mm / tooth, determined by the material and tool); Z is the number of tool teeth; and S is the spindle speed (rpm). For example, if a φ10mm four-edge milling cutter is machining steel, with Fz = 0.08mm / tooth and S = 1500rpm, then F = 480mm / min. Therefore, a phased feed rate optimization strategy is as follows: During roughing, prioritize high material removal rates. This means: Fz is set to an upper limit, such as 0.12–0.4 mm / tooth for steel, to improve cutting efficiency and reduce working time. For depth of cut coordination, the radial depth of cut (Ae) is kept ≤ 75% of the tool diameter to avoid tool overload. The feed rate is maintained at the maximum allowed by the machine power to fully utilize the equipment's potential. Subsequently, during finishing, prioritize surface quality. For example, Fz is set to a lower limit, such as 0.02–0.05 mm / tooth for aluminum alloys, to reduce cutting forces and minimize chatter marks. For depth of cut control, the axial depth of cut (Ap) is set to 0.1–0.5 mm to ensure dimensional accuracy. For surface roughness control, F is set to ≤ 50 mm / min to achieve Ra ≤ 1.6 μm, thus meeting high finish requirements.

[0031] Furthermore, the present invention provides a production process for injection molds and continues to propose a genetic algorithm parameter optimization method, which is a method that automatically matches the parameter combination for the highest material removal rate (MRR) under the constraints of cutting force ≤ machine tool rigidity limit and temperature ≤ material critical value through iterative calculation.

[0032] Specifically, first, we designed the algorithm framework, such as constructing the objective function, which takes maximizing the material removal rate (MRR) as the core goal and establishes a mathematical model based on the constraints as follows:

[0033] Among them, Fc is the cutting force, T is the cutting temperature, Fmax and Tcrit are the limit values ​​of machine tool and material.

[0034] Next, set the encoding method. For example, if real number encoding is used, the chromosome contains spindle speed (S), feed rate (fz), axial cutting depth (a p )、Radial cutting depth(a e ) and other parameters to directly map the actual processing range.

[0035] Constraint processing techniques are then employed, including penalty functions, which impose penalties on out-of-bounds parameters. For example, when cutting force exceeds the limit, the MRR value is proportionally decayed, forcing the population to converge to the feasible region. For example, if Fc > Fmax, the fitness is adjusted to MRR × (1-(Fc-Fmax) / Fmax). Furthermore, feasibility rules can be set. For example, after crossover mutation, parameters are corrected through boundary checks: cutting depths exceeding the machine tool's rigidity limits are automatically adjusted to the upper limit; individuals with excessive temperatures are directly eliminated.

[0036] In summary, the method for optimizing parameters using a genetic algorithm for a production process of an injection mold according to the present invention comprises the following steps: S11: Initial population generation, randomly generating 100–500 solutions within the parameter feasible region, covering typical roughing / finishing combinations, such as S = 6,000–10,000 rpm, fz = 0.05–0.2 mm / tooth; S12: Fitness evaluation, calling cutting simulation models such as AdvantEdge or Deform to calculate the MRR, cutting force and temperature of each group, and screening the Pareto frontier solution; S13: Genetic operations: a. Selection, using tournament selection to retain the top 20% individuals in terms of fitness; b. Crossover, arithmetic crossover to generate new solutions by weighted averaging of parent parameters; c. Mutation, Gaussian perturbation mutation with a standard deviation set to 5%–10% of the parameter range; S14: Termination condition, stop when the change rate of the optimal solution for 10 consecutive generations is less than 1% or the maximum number of iterations (usually 100–200 generations) is reached.

[0037] Furthermore, for the above-mentioned genetic algorithm parameter optimization method, a more specific step is as follows:

[0038] S111: Parameter encoding, using real number encoding. The chromosome includes spindle speed (S), feed per tooth (Fz), axial depth of cut (Ap), and radial depth of cut (Ae). The range is set according to the machine tool specifications, such as S∈[5000,12000] rpm. The constraints are as follows: Wherein, Kc is the material cutting force coefficient; S112: Randomly generate 200-500 parameter combinations to cover typical machining scenarios, such as rough machining Ap=3-6mm, fine machining Fz=0.02-0.1mm / tooth; S113: The judgment formula of the multi-objective fitness function is as follows:

[0039] Among them, the weight W1+W2+W3=1, adjusted according to the priority, such as roughing M1=0.7; and the MRR, cutting force Fc, and surface roughness Ra are calculated through cutting simulation or empirical formula; S114: Elite retention strategy, which retains the top 10% of individuals in fitness in each generation and directly enters the next generation to avoid the loss of high-quality solutions; S115: Adaptive crossover and mutation, linear combination of parent parameters, such as offspring

[0040] Gaussian mutation, the mutation intensity decreases with the number of iterations, and the standard deviation

[0041] S116: Constraint processing, the out-of-bounds parameters use the reflective boundary method, such as S>Smax is reset to 2Smax-S; the temperature exceeds the limit of the individual triggers a dynamic penalty: fitness multiplied by e -(T-Tcrit) / 50 ; S117: Convergence judgment: terminate when the optimal fitness changes by less than 1% for 15 consecutive generations or reaches the maximum number of generations, usually 100-150 generations; output the Pareto frontier solution set for the user to select; S118: Post-processing verification: Perform cutting simulation verification (such as Deform-3D) or small-batch trial cutting on the optimal solution to detect the actual cutting force / temperature error (required to be ≤5%).

[0042] In the above method, the key parameter designs are shown in Table 2 below: Table 2: Key parameter design

[0043] Based on the aforementioned method of genetic algorithm parameter optimization proposed in the present invention for the production process of an injection mold, the optimization results are shown in Table 3 below: Table 3: Optimization results

[0044] In summary, the production process of an injection mold of the present invention first performs demand analysis and mold design through CAD software to ensure the rationality of the cavity, runner, cooling system and exhaust structure; then selects mold steel or aluminum such as P20 and H13 for material preparation; then performs preliminary molding of the module through rough processing, and then adopts precision processing technologies such as CNC and electric spark to achieve ±0.01mm accuracy; then performs mirror polishing and heat treatment to improve surface quality and wear resistance; after completing assembly and debugging, optimizes injection molding parameters through trial mold; finally uses a three-coordinate measuring instrument to perform full-size inspection and correction to ensure that the mold meets the design standards; the production process proposed by the production process of an injection mold of the present invention takes into account the requirements of accuracy, efficiency and durability, and can improve the production efficiency of the injection mold. Therefore, the production process of an injection mold of the present invention solves the technical problem of how to improve the production efficiency of the injection mold.

[0045] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0046] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A production process for an injection mold, characterized in that: It includes the following steps: S1: Demand analysis and mold design. Based on the preset product specifications and material properties, the 3D modeling of the injection mold is completed using CAD software. The cavity, runner system, and cooling water channel are designed as required. At the same time, the draft angle and exhaust system are designed. S2: Material preparation, choose mold steel, such as P20, H13 high wear-resistant steel, etc. or aluminum; S3: Rough machining, using a lathe or milling machine to cut the blank and preliminarily form the module and hole slots; S4: Finishing, using at least one of CNC precision machining, EDM, laser machining, and 3D printing; and using high-speed light cutting strategies as well as thermal management and precision control strategies to process the curved surfaces of injection molds; S5: Surface treatment: Grinding and polishing the mold cavity and other structures of the injection mold to a mirror-grade finish, meeting the requirement of Ra ≤ 0.1μm; heat treatment, quenching and tempering to increase the hardness of the injection mold to HRC 48-52; S6: Assembly and debugging: assemble the mold core, slider, ejector and other components, and check the matching accuracy; then adjust the injection molding parameters such as temperature, pressure, cycle, etc. through trial molds to verify the demoulding smoothness and product size; S7: Inspection, use a three-coordinate measuring machine to perform full-size inspection of the injection mold, compare it with the design tolerance and correct the deviation size in turn.

2. The production process of an injection mold according to claim 1, characterized in that: During the roughing and finishing processes, the cutting speed and spindle speed are balanced according to the material properties of the injection mold being processed.

3. The production process of an injection mold according to claim 2, characterized in that: When milling aluminum alloys, the cutting speed is controlled at 2000–7500 m / min at spindle speeds ≥18,000 rpm. When milling titanium alloys or hardened steel, the cutting speed is reduced to 150–300 m / min at spindle speeds in the range of 8,000–15,000 rpm.

4. The production process of an injection mold according to claim 1, characterized in that: During roughing and finishing operations, the feed rate is controlled by the formula F = Fz × Z × S. Here, Fz is the feed per tooth in mm / tooth; Z is the number of tool teeth; and S is the spindle speed in rpm.

5. The production process of an injection mold according to claim 4, characterized in that: For the processing of aluminum alloys, Fz is 0.02–0.1 mm / tooth; for the processing of titanium alloys or hardened steel, Fz is reduced to 0.05–0.08 mm / tooth.

6. The production process of an injection mold according to claim 5, characterized in that: For thin-walled parts, a combination of small cutting depth (Ap≤0.5mm) and high feed (F≥2500 mm / min) is used.

7. The production process of an injection mold according to claim 1, characterized in that: During roughing and finishing operations, the depth of cut is controlled in layers. For deep cavity machining, the axial depth of cut (Ap) is limited to 0.8 times the tool diameter; for highly rigid workpieces, this is increased to 1.2 times the tool diameter. For finishing, the radial depth of cut (Ae) is limited to 10% of the tool diameter; for roughing, the depth of cut is limited to 70% of the tool diameter.

8. The production process of an injection mold according to claim 1, characterized in that: Through iterative calculation, under the constraints of cutting force ≤ machine tool rigidity limit and temperature ≤ material critical value, the parameter combination with the highest material removal rate (MRR) is automatically matched according to the preset algorithm.

9. The production process of an injection mold according to claim 8, characterized in that: The specific steps for automatically matching the parameter combination with the highest material removal rate MRR according to the preset algorithm are as follows: S11: Initial population generation, randomly generating 100–500 solutions within the parameter feasible region, covering typical roughing / finishing combinations; S12: Fitness evaluation, calling the cutting simulation model to calculate the MRR, cutting force and temperature of each group, and screening the Pareto frontier solution; S13: Genetic operations: a. Selection, using tournament selection to retain the top 20% individuals in terms of fitness; b. Crossover‌, arithmetic crossover, generates new solutions by weighted averaging of parent parameters; c. Mutation‌, Gaussian perturbation mutation, with the standard deviation set to 5%–10% of the parameter range; S14: Termination condition: stop when the change rate of the optimal solution for 10 consecutive generations is less than 1% or the maximum number of iterations is reached.

Images