Modified master batch for vehicle steering worm gear as well as preparation method and application of modified master batch

Abstract

The invention relates to the technical field of vehicle steering gears, in particular to a modified master batch for a vehicle steering worm gear and a preparation method thereof, a composite material for the vehicle steering worm gear and a preparation method thereof, the vehicle steering worm gear and a preparation method thereof, a vehicle steering gear and a vehicle. The modified master batch for the vehicle steering worm gear comprises the following components in parts by weight: 3-8 parts of a heat stabilizer; 3-8 parts by weight of an antioxidant; 5-10 parts by weight of a flow modifier; 5-10 parts by weight of a lubricant; and 3-8 parts by weight of an anti-hydrolysis agent. The modified master batch can effectively improve the thermal stability and melt fluidity of matrix resin, reduce the influence of the injection molding process on the viscosity of the matrix resin, and ensure the performance of the matrix resin, thereby improving the mechanical properties, frictional wear properties and fatigue resistance of a composite material adopting the modified master batch. And the characteristics of torque, service life and the like of the worm gear made of the composite material are improved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle steering gears, and more specifically to a modified masterbatch for a vehicle steering worm gear and a preparation method and application thereof, and more specifically to a modified masterbatch for a vehicle steering worm gear and a preparation method thereof, a composite material for a vehicle steering worm gear and a preparation method thereof, a vehicle steering worm gear and a preparation method thereof, a vehicle steering gear and a vehicle. Background Art

[0002] The worm gear is a key component of the EPS electronic power steering system, which is used in conjunction with the worm to transmit the power. The worm gear mainly adopts a composite structure design of a plastic material coated with a metal insert. The metal insert meets the high assembly precision requirements of the worm gear, and the nylon material provides the worm gear with high torque, wear resistance, low noise and other properties. The nylon material in the current worm gear still has problems such as easy cracking, high price, and mechanical properties, friction and wear properties, and fatigue resistance that do not meet the requirements, which in turn affects the torque and service life of the turbine. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, the present invention provides a modified masterbatch for a vehicle steering worm gear having higher mechanical properties, better friction and wear properties or better fatigue resistance and a preparation method thereof, a composite material for a vehicle steering worm gear and a preparation method thereof, a vehicle steering worm gear and a preparation method thereof, a vehicle steering gear and a vehicle.

[0004] In the first aspect of the present application, a modified masterbatch for vehicle steering worm gear is provided. According to an embodiment of the present application, the modified masterbatch includes: 3 to 8 parts by weight of thermal stabilizer; 3 to 8 parts by weight of antioxidant; 5 to 10 parts by weight of flow modifier; 5 to 10 parts by weight of lubricant; 3 to 8 parts by weight of anti-hydrolysis agent. The modified masterbatch can effectively improve the thermal stability and melt fluidity of the matrix resin, reduce the influence of the injection molding process on the viscosity of the matrix resin, ensure the performance of the matrix resin, and thus improve the mechanical properties, friction and wear properties, and fatigue resistance of the composite material using the modified masterbatch, thereby improving the torque, service life and other characteristics of the worm gear using the above composite material.

[0005] According to an embodiment of the present application, the modified masterbatch further comprises: 56 to 81 parts by weight of the base resin. Thus, when used, the modified masterbatch has better compatibility with the base resin and is easier to mix evenly.

[0006] According to an embodiment of the present application, the matrix resin includes at least one of PA66 (polyamide 66, or nylon 66), PA46 (polyamide 46, or nylon 46), semi-aromatic nylon and PEEK (polyetheretherketone). The matrix resin has the characteristics of high strength, high modulus, high toughness, friction and wear resistance, fatigue resistance, etc., and also has excellent thermal stability and melt fluidity and other process properties. When used for vehicle steering worm gears, it can effectively improve the torque and service life of the worm gear.

[0007] According to an embodiment of the present application, the relative viscosity of the base resin is ≥4.8; and the viscosity number of the base resin is ≥280. Thus, the performance of the base resin can be further improved.

[0008] According to an embodiment of the present application, the PA66 includes LEONATM 1702, LEONATM 1700S, RADILON A50HSKB, S240C, A5H、Ascend At least one of 67B. The above-mentioned PA66 has the characteristics of high strength, high modulus, high toughness, friction and wear resistance, fatigue resistance, etc., and also has excellent process properties such as thermal stability and melt fluidity. When used in vehicle steering worm gears, it can effectively improve the torque and service life of the worm gear.

[0009] According to an embodiment of the present application, the thermal stabilizer includes at least one of an alkali metal halide and a cuprous halide. In some embodiments, the thermal stabilizer includes a mixture of the alkali metal halide and the cuprous halide in a mass ratio of 1:1 to 10:1. As an example, the alkali metal halide includes at least one of potassium iodide and potassium bromide. As an example, the cuprous halide includes at least one of cuprous iodide and cuprous chloride.

[0010] According to an embodiment of the present application, the antioxidant includes at least one of a hindered phenol antioxidant, a phosphite antioxidant and a hindered amine antioxidant. As an example, the antioxidant includes at least one of 1010, 1076, 1098, 245, 168, 626, DNP, DLTP, TNP, TPP, and MB.

[0011] According to an embodiment of the present application, the flow modifier includes at least one of ultra-high molecular weight silicone polymer, hyperbranched polyester, hyperbranched polymer and dendritic polymer. As an example, the flow modifier includes at least one of CYD-816A, CYD-817, CYD-818, CYD-819, H20P, H30P, H40P.

[0012] According to an embodiment of the present application, the lubricant includes at least one of polytetrafluoroethylene powder, molybdenum disulfide powder, graphite powder, fatty acids and their esters, fatty acid amides, metal soaps and alkane lubricants. As an example, the lubricant includes at least one of polytetrafluoroethylene powder with a particle size of 1 μm to 10 μm, molybdenum disulfide powder with a particle size of 50 μm to 100 μm, graphite powder with a particle size of 1 μm to 50 μm, silicone powder, polyethylene wax, montan wax, amide wax, vinyl bis stearamide, calcium stearate, zinc stearate, sodium stearate and barium stearate.

[0013] According to an embodiment of the present application, the anti-hydrolysis agent includes at least one of polycarbodiimide and carbodiimide compounds.

[0014] According to an embodiment of the present application, the particle size of the modified masterbatch is 3 mm to 5 mm.

[0015] In a second aspect, the present application provides a method for preparing the modified masterbatch described above. According to an embodiment of the present application, the method comprises: mixing the raw materials of the modified masterbatch to obtain a raw material mixture; and granulating the raw material mixture to obtain the modified masterbatch.

[0016] According to an embodiment of the present application, the raw material mixture contains a base resin, and the water content of the base resin is less than 0.05%.

[0017] In the third aspect of the present application, a composite material for a vehicle steering turbine is provided. According to an embodiment of the present application, the composite material comprises: 94 to 97 parts by weight of a matrix resin; and 3 to 6 parts by weight of the modified masterbatch described above. The composite material has the characteristics of high strength, high modulus, high toughness, friction and wear resistance, fatigue resistance, etc. When used for a vehicle steering worm gear, it can effectively improve the torque and service life of the worm gear.

[0018] According to an embodiment of the present application, based on the total mass of the composite material, the content of copper element in the composite material is ≥100 ppm.

[0019] In a fourth aspect of the present application, a method for preparing the composite material described above is provided. According to an embodiment of the present application, the method comprises: mixing the modified masterbatch described above with a matrix resin, and performing injection molding on the obtained mixture to obtain the composite material. The method is simple and convenient to operate, and the matrix resin does not need to be modified by a twin-screw extruder, and the matrix resin can maintain a high viscosity and good performance, is not easy to hydrolyze, and thus improves the performance of the composite material.

[0020] In a fifth aspect of the present application, a vehicle steering worm gear is provided. According to an embodiment of the present application, the vehicle steering worm gear comprises: a metal insert; a composite material part, the composite material part wraps the edge of the metal insert, and the composite material part comprises the composite material described above. The vehicle steering worm gear can not only meet the high assembly precision requirements of the worm gear, but also has the performances of high torque, wear resistance, low noise, etc.

[0021] According to an embodiment of the present application, the metal insert includes: an inner ring; an outer ring, the outer ring is embedded in the composite material part, and a plurality of straight teeth arranged at intervals along the circumference of the outer ring are provided on the side of the outer ring away from the inner ring, and the straight teeth are located in the middle of the composite material part in the thickness direction; and a connecting part, the connecting part is connected between the inner ring and the outer ring.

[0022] According to an embodiment of the present application, the metal insert has a first side and a second side opposite to each other in the thickness direction, the outer ring protrudes toward the second side relative to the connecting portion, and the distance between the surface of the inner ring facing the first side and the surface of the connecting portion facing the first side is 1 mm to 3 mm.

[0023] According to an embodiment of the present application, a surface of the inner ring facing the first side is connected to a surface of the connecting portion facing the first side via an inclined surface.

[0024] According to an embodiment of the present application, the acute angle between the inclined surface and the surface of the inner ring facing the first side is 15° to 60°.

[0025] In a sixth aspect of the present application, a method for preparing the aforementioned vehicle steering worm gear is provided. According to an embodiment of the present application, the method comprises: preheating a metal insert to obtain a preheated metal insert; placing the preheated metal insert in an injection mold, and injecting the aforementioned mixture of modified masterbatch and matrix resin into the injection mold to form a composite material on at least a portion of the surface of the metal insert to obtain an injection molded product; processing the injection molded product to remove a portion of the composite material to obtain the vehicle steering worm gear.

[0026] According to an embodiment of the present application, the injection molding of the mixture of the modified masterbatch and the matrix resin into the injection mold includes: injecting the mixture into the injection mold, then demolding, and cooling the injection molded product obtained after demolding at a temperature of 40°C to 80°C.

[0027] According to an embodiment of the present application, after the cooling, the injection molded product is placed at a temperature of 60° C. to 100° C. and kept warm for 6 h to 12 h.

[0028] In a seventh aspect, the present application provides a vehicle steering gear. According to an embodiment of the present application, the vehicle steering gear includes the vehicle steering worm gear described above. The vehicle steering gear has all the features and advantages of the vehicle steering worm gear described above, which will not be described one by one here.

[0029] In an eighth aspect of the present application, a vehicle is provided. According to an embodiment of the present application, the vehicle includes the vehicle steering worm gear or the vehicle steering gear described above. The vehicle has all the features and advantages of the vehicle steering worm gear or vehicle steering gear described above, which will not be described one by one here.

[0030] This application has at least the following beneficial effects:

[0031] (1) The composite material modified by the modified masterbatch of the present application is used for a worm gear, which can reduce the waste of matrix resin and reduce costs while ensuring that the pull-out force between the composite material part and the metal insert and the bonding torque between the metal insert and the composite material part meet the requirements.

[0032] (2) By using modified masterbatch, the base resin does not need to be blended and modified by a twin-screw extruder during the preparation of the worm gear, which can improve the problem of base resin degradation caused by screw shearing during the blending and modification of the twin-screw extruder, thereby reducing the performance loss of the composite material.

[0033] (3) The heat stabilizer and flow modifier in the modified masterbatch can improve the thermal stability and melt fluidity of the matrix resin, reduce the impact of the injection molding process on the viscosity of the matrix resin, and ensure that the performance of the matrix resin meets the requirements of the worm gear.

[0034] (4) During the injection molding process of the worm gear, the matrix resin is in a molten state in the screw and is cooled to a solid state after being injected into the mold. Rapid cooling will cause large shrinkage, and the presence of metal inserts will cause internal stress concentration in the matrix resin, which is prone to cracking. After demolding, place it in an environment of 40℃ to 80℃ for cooling. Slow cooling can slow down the shrinkage rate and reduce internal stress and cracking risks.

[0035] (5) After the worm gear is cooled by injection molding, further heat treatment can further reduce the internal stress of the worm gear and avoid cracking during machining. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic structural diagram of a vehicle steering worm gear according to an embodiment of the present application.

[0037] Figure 2 It is a schematic structural diagram of a vehicle steering worm gear according to another embodiment of the present application.

[0038] Figure 3 It is a schematic structural diagram of a vehicle steering worm gear according to another embodiment of the present application.

[0039] Figure 4 It is a schematic structural diagram of a vehicle steering worm gear according to another embodiment of the present application.

[0040] Figure 5 It is a schematic diagram of the structure of the injection molded product in Example 1 of the present application.

[0041] Figure 6 It is a schematic diagram of the press-release test fixture between the metal insert and the composite material part of the present application.

[0042] Figure 7 It is a schematic diagram of the torque test fixture between the metal insert and the composite material part of the present application.

[0043] Reference numerals:

[0044] 10: Metal insert 11: Inner ring 101: First side 102: Second side 111: Surface of inner ring facing the first side 12: Outer ring 121: Straight teeth 122: Side of outer ring facing away from inner ring 13: Connecting part 131: Surface of connecting part facing the first side 100, 200: Inclined surface 20: Composite material part DETAILED DESCRIPTION

[0045] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0046] In the first aspect of the present application, a modified masterbatch for a vehicle steering worm gear is provided. According to an embodiment of the present application, the modified masterbatch comprises: 3 to 8 parts by weight of a heat stabilizer; 3 to 8 parts by weight of an antioxidant; 5 to 10 parts by weight of a flow modifier; 5 to 10 parts by weight of a lubricant; and 3 to 8 parts by weight of an anti-hydrolysis agent.

[0047] Specifically, the amount of heat stabilizer can be 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, etc.; the amount of antioxidant can be 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, etc.; the amount of flow modifier can be 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, etc.; the amount of lubricant can be 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, etc.; the amount of anti-hydrolysis agent can be 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, etc.

[0048] The modified masterbatch can effectively improve the thermal stability and melt fluidity of the matrix resin, reduce the influence of the injection molding process on the viscosity of the matrix resin, ensure the performance of the matrix resin, and further improve the strength, modulus, friction and wear performance, fatigue resistance and dimensional stability of the composite material using the modified masterbatch, thereby improving the torque and service life of the worm gear using the modified masterbatch.

[0049] According to an embodiment of the present application, the modified masterbatch also includes: 56 to 81 parts by weight of the base resin. Specifically, the amount of the base resin can be 56 parts by weight, 58 parts by weight, 60 parts by weight, 62 parts by weight, 65 parts by weight, 68 parts by weight, 70 parts by weight, 72 parts by weight, 75 parts by weight, 78 parts by weight, 80 parts by weight, 81 parts by weight, etc. Therefore, when used, the modified masterbatch has better compatibility with the base resin, and the components in the modified masterbatch are easier to mix evenly in the base resin, and then the base resin modified by the modified masterbatch has better performance.

[0050] According to an embodiment of the present application, the relative viscosity of the matrix resin is ≥4.8, specifically 5.0; the viscosity number of the matrix resin is ≥280, specifically 300. In this way, the performance of the matrix resin can be further improved. The matrix resin with the above-mentioned high viscosity has the characteristics of high strength, high modulus, high toughness, friction and wear resistance, fatigue resistance, and other properties, as well as excellent thermal stability and melt fluidity and other process properties. During the injection molding process of the worm wheel blank, the degradation of the matrix resin can be reduced to ensure that the worm wheel has the characteristics of high torque, long service life, etc.

[0051] In this article, relative viscosity refers to the ratio of the dynamic viscosity of the matrix resin solution to the dynamic viscosity of the solvent at the same temperature, which can be tested by the ASTM D789 method; viscosity number refers to the viscosity of the dilute solution of the matrix resin in certain solvents, which can be tested by the sulfuric acid method in ISO 307.

[0052] According to an embodiment of the present application, the matrix resin includes at least one of PA66 (polyamide 66, or nylon 66), PA46 (polyamide 46, or nylon 46), semi-aromatic nylon and PEEK (polyetheretherketone). The matrix resin has the characteristics of high strength, high modulus, high toughness, friction and wear resistance, fatigue resistance, etc., and also has excellent thermal stability and melt fluidity and other process properties. When used for vehicle steering worm gears, it can effectively improve the torque, wear resistance, low noise and long service life of the worm gear.

[0053] In some embodiments, the PA66 may include LEONATM 1702, LEONATM 1700S, RADILONA50HSKB, S240C, A5H、Ascend At least one of 67B. The above-mentioned PA66 has the characteristics of high strength, high modulus, high toughness, friction and wear resistance, fatigue resistance, etc., and also has excellent process performances such as thermal stability and melt fluidity. When used for vehicle steering worm gears, it can effectively improve the torque, wear resistance, low noise and long service life of the worm gears.

[0054] According to an embodiment of the present application, the thermal stabilizer includes at least one of an alkali metal halide and a cuprous halide. In some embodiments, the thermal stabilizer includes a mixture of the alkali metal halide and the cuprous halide in a mass ratio of 1:1 to 10:1. As an example, the alkali metal halide includes at least one of potassium iodide and potassium bromide. As an example, the cuprous halide includes at least one of cuprous iodide and cuprous chloride. The above-mentioned thermal stabilizer can effectively improve the thermal stability of the base resin. Under shearing, the base resin using the thermal stabilizer is not prone to thermal oxidative aging, degradation, yellowing, and has good fluidity and resistance to thermal oxidative aging.

[0055] According to an embodiment of the present application, the antioxidant includes at least one of a hindered phenol antioxidant, a phosphite antioxidant and a hindered amine antioxidant. As an example, the antioxidant includes at least one of 1010, 1076, 1098, 245, 168, 626, DNP, DLTP, TNP, TPP, and MB. The use of the above antioxidants can effectively improve the antioxidant properties of the matrix resin, and the material source is wide, the cost is low, and the compatibility with the matrix resin is good.

[0056] According to an embodiment of the present application, the flow modifier includes at least one of ultra-high molecular weight silicone polymer, hyperbranched polyester, hyperbranched polymer and dendritic polymer. As an example, the flow modifier includes at least one of CYD-816A, CYD-817, CYD-818, CYD-819, H20P, H30P, and H40P. By using the above flow modifier, the fluidity of the matrix resin is effectively improved, and the injection molding process is easier to achieve.

[0057] According to an embodiment of the present application, the lubricant includes at least one of polytetrafluoroethylene powder, molybdenum disulfide powder, graphite powder, fatty acids and their esters, fatty acid amides, metal soaps and alkane lubricants. As an example, the lubricant includes polytetrafluoroethylene powder with a particle size of 1 μm to 10 μm, molybdenum disulfide powder with a particle size of 50 μm to 100 μm, graphite powder with a particle size of 1 μm to -50 μm, silicone powder, polyethylene wax, montan wax, amide wax, vinyl bis stearamide, calcium stearate, zinc stearate, sodium stearate and barium stearate. As a result, the matrix resin has better lubricity, is easy to demold, and the appearance of the product after injection molding is smoother and smoother.

[0058] Herein, the particle size of a material refers to the average particle size of particles of different sizes of the material, which can be detected by laser diffraction method.

[0059] According to an embodiment of the present application, the anti-hydrolysis agent includes at least one of polycarbodiimide and carbodiimide compounds, thereby effectively inhibiting the hydrolysis of the base resin and alleviating the performance degradation problem caused by the hydrolysis of the base resin during processing.

[0060] According to the embodiments of the present application, the particle size of the modified masterbatch is 3 mm to 5 mm, specifically 3 mm, 3.2 mm, 3.5 mm, 3.8 mm, 4 mm, 4.2 mm, 4.5 mm, 4.8 mm, 5 mm, etc. With the above particle size, it is easier to mix evenly with the base resin and better play the modification role.

[0061] In a second aspect, the present application provides a method for preparing the modified masterbatch described above. According to an embodiment of the present application, the method comprises: mixing the raw materials of the modified masterbatch to obtain a raw material mixture; and granulating the raw material mixture to obtain the modified masterbatch.

[0062] Specifically, in this step, the raw materials of the modified masterbatch can be mixed using a mixer. As an example, the raw materials of the modified masterbatch can be added to the mixer and mixed for 10 minutes to 15 minutes to obtain a raw material mixture.

[0063] Specifically, according to actual use needs, the raw material mixture of this step may include the base resin or may not include the base resin. In some embodiments, the raw materials of the modified masterbatch include 3 to 8 parts by weight of heat stabilizer; 3 to 8 parts by weight of antioxidant; 5 to 10 parts by weight of flow modifier; 5 to 10 parts by weight of lubricant; 3 to 8 parts by weight of anti-hydrolysis agent. In other embodiments, the raw materials of the modified masterbatch include 56 to 81 parts by weight of base resin; 3 to 8 parts by weight of heat stabilizer; 3 to 8 parts by weight of antioxidant; 5 to 10 parts by weight of flow modifier; 5 to 10 parts by weight of lubricant; 3 to 8 parts by weight of anti-hydrolysis agent.

[0064] According to the embodiment of the present application, before the raw materials of the modified masterbatch are mixed, the base resin can be dried in advance. Specifically, the base resin can be placed in a drying oven for drying, the drying temperature can be 80°C to 120°C, and the drying time can be 4h to 12h, so that the water content of the base resin is less than 0.05%; that is, the raw material mixture contains the base resin, and the water content of the base resin is less than 0.05%. In this way, the hydrolysis of the base resin during the processing can be effectively suppressed, which is conducive to improving the performance of the base resin.

[0065] In some embodiments, granulation can be performed using a twin-screw extruder and a pelletizer. Specifically, the raw material mixture can be added to the twin-screw extruder, the screw temperature and speed can be adjusted to perform blending modification, and the pelletizer speed can be controlled to control the particle size of the modified masterbatch to be 3 mm to 5 mm.

[0066] It can be understood that in this method, the base resin, heat stabilizer, antioxidant, flow modifier, lubricant, anti-hydrolysis agent, etc. can be consistent with the above description and will not be described in detail here.

[0067] In a third aspect, the present application provides a composite material for a vehicle steering worm gear. According to an embodiment of the present application, the composite material comprises: 94 to 97 parts by weight of a matrix resin; and 3 to 6 parts by weight of the modified masterbatch described above.

[0068] Specifically, in the composite material, the amount of the matrix resin can be 94 parts by weight, 94.5 parts by weight, 95 parts by weight, 95.5 parts by weight, 96 parts by weight, 96.5 parts by weight, or 97 parts by weight; the amount of the modified masterbatch mentioned above can be 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight, 5 parts by weight, 5.5 parts by weight, 6 parts by weight, etc.

[0069] The composite material has the characteristics of high strength, high modulus, high toughness, friction and wear resistance, fatigue resistance, etc. When used in vehicle steering worm gears, it can effectively improve the torque and service life of the worm gears.

[0070] According to an embodiment of the present application, based on the total mass of the composite material, the content of copper in the composite material is ≥100 ppm. Specifically, the copper in the composite material mainly comes from the thermal stabilizer, and the copper content is within the above range, which can effectively improve the thermal stability of the composite material and inhibit the thermal oxidation of the matrix resin during processing and reduce the performance.

[0071] In a fourth aspect of the present application, a method for preparing the composite material described above is provided. According to an embodiment of the present application, the method comprises: mixing the modified masterbatch described above with a matrix resin, and performing injection molding on the obtained mixture to obtain the composite material. The method is simple and convenient to operate, and the matrix resin does not need to be modified by a twin-screw extruder, and the matrix resin can maintain a high viscosity and good performance, is not easy to hydrolyze, and thus improves the performance of the composite material.

[0072] According to the embodiment of the present application, the base resin and the modified masterbatch can be mixed uniformly in proportion by a mixer, and then placed in a drying oven for drying, the drying temperature can be 80°C to 120°C, the time can be 4h to 12h, and the water content of the mixture of the base resin and the modified masterbatch is less than 0.05%. In this way, the hydrolysis of the base resin can be effectively inhibited, which is conducive to improving the performance of the composite material.

[0073] Furthermore, the dried mixture of the base resin and the modified masterbatch can be added to the hopper of the injection molding machine so that the temperature of the injection mold is 80°C to 150°C, the injection molding machine can use a 160-250T machine, the screw temperature can be 270°C to 290°C, the hot runner temperature can be 200°C to 265°C, and the injection pressure, injection time, holding pressure and holding time can be appropriately selected and adjusted according to the size of the composite material.

[0074] After the injection molded composite material is formed, it can be demolded and then slowly cooled in a 40°C to 80°C environment to avoid rapid cooling of the composite material, which may cause cracking. Next, the cooled composite material can be placed in a 60°C to 100°C oven for post-treatment for 6h to 12h to remove internal stress of the composite material and avoid cracking of the composite material during processing and transportation.

[0075] In a fifth aspect of the present application, a vehicle steering worm gear is provided. According to an embodiment of the present application, referring to Figure 1 and Figure 2 The vehicle steering worm gear comprises: a metal insert 10; a composite material part 20, wherein the composite material part 20 wraps the edge of the metal insert 10, and the composite material part 20 comprises the composite material mentioned above. The vehicle steering worm gear can not only meet the high assembly precision requirements of the worm gear, but also has the performances of high torque, wear resistance, low noise, long service life, etc.

[0076] It is understood that the structure and material of the metal insert can be selected according to actual needs. In some embodiments, the material of the metal insert includes but is not limited to 20# steel, 25# steel, 45# steel, etc.

[0077] According to the embodiments of the present application, referring to Figure 3 and Figure 4 The metal insert 10 comprises: an inner ring 11; an outer ring 12, the outer ring 12 is embedded in the composite material 20, and a plurality of straight teeth 121 arranged at intervals along the circumference of the outer ring 12 are arranged on the side of the outer ring 12 away from the inner ring 11, and the straight teeth 121 are located in the middle of the composite material 20 in the thickness direction; and a connecting portion 13, the connecting portion 13 is connected between the inner ring 11 and the outer ring 12. Such an arrangement can greatly improve the press-off force between the metal insert and the composite material.

[0078] According to the embodiments of the present application, referring to Figure 4 The metal insert 10 has a first side 101 and a second side 102 opposite to each other in the thickness direction. The side surface 122 of the outer ring 12 facing away from the inner ring 11 and the surface 131 of the connecting portion 13 facing the first side 101 are connected by an inclined surface 100. The acute angle α between the inclined surface 100 and the surface 131 of the connecting portion 13 facing the first side 101 is 20° to 45°. Thus, the spur teeth 121 can be located in the middle of the composite material part 20 in the thickness direction, which is conducive to improving the press-off force between the metal insert and the composite material.

[0079] According to the embodiments of the present application, referring to Figure 4 The metal insert 10 has a first side 101 and a second side 102 opposite to each other in the thickness direction, the outer ring 12 protrudes toward the second side 102 relative to the connecting portion 13, and the distance between the surface 111 of the inner ring 11 facing the first side 101 and the surface 131 of the connecting portion 13 facing the first side 101 is 1 mm to 3 mm (specifically, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3 mm, etc.). Thus, the distance between the surface 111 of the inner ring 11 facing the first side 101 and the surface 131 of the connecting portion 13 facing the first side 101 is small, and the gap between the inner ring 11 and the mold is small during injection molding, which can save the amount of matrix resin and reduce costs.

[0080] According to the embodiments of the present application, referring to Figure 4The surface 111 of the inner ring 11 facing the first side 101 is connected to the surface 131 of the connecting portion 13 facing the first side 101 through the inclined surface 200. This arrangement can effectively improve the problem of air holes generated by air encapsulation during injection molding and improve the injection molding quality.

[0081] According to the embodiments of the present application, referring to Figure 4 The acute angle β between the inclined surface 200 and the surface 111 of the inner ring 11 facing the first side 101 is 15° to 60°. Thus, the problem of air holes caused by air encapsulation during injection molding can be further improved, thereby improving the injection molding quality.

[0082] It is understandable that the specific shape and structure of the metal insert and the composite material part can be designed according to actual use requirements, for example, by referring to conventional techniques, and there is no particular limitation in this application.

[0083] In a sixth aspect of the present application, a method for preparing the aforementioned vehicle steering worm gear is provided. According to an embodiment of the present application, the method comprises: preheating a metal insert to obtain a preheated metal insert; placing the preheated metal insert in an injection mold, and injecting the aforementioned mixture of modified masterbatch and matrix resin into the injection mold to form a composite material on at least a portion of the surface of the metal insert to obtain an injection molded product; processing the injection molded product to remove a portion of the composite material to obtain the vehicle steering worm gear.

[0084] According to an embodiment of the present application, the injection molding of the mixture of the modified masterbatch and the matrix resin into the injection mold includes: injecting the mixture into the injection mold, then demolding, and cooling the injection molded product obtained after demolding at a temperature of 40°C to 80°C.

[0085] According to an embodiment of the present application, after the cooling, the injection molded product is placed at a temperature of 60° C. to 100° C. and kept warm for 6 h to 12 h.

[0086] In a seventh aspect, the present application provides a vehicle steering gear. According to an embodiment of the present application, the vehicle steering gear includes the vehicle steering worm gear described above. The vehicle steering gear has all the features and advantages of the vehicle steering worm gear described above, which will not be described one by one here.

[0087] In an eighth aspect of the present application, a vehicle is provided. According to an embodiment of the present application, the vehicle includes the vehicle steering worm gear or the vehicle steering gear described above. The vehicle has all the features and advantages of the vehicle steering worm gear or vehicle steering gear described above, which will not be described one by one here.

[0088] The embodiments of the present application are described in detail below.

[0089] Example 1

[0090] The composite material formula is as follows:

[0091]

[0092] The worm gear preparation process is as follows:

[0093] (1) Modified masterbatch preparation process:

[0094] 1) Drying of the matrix resin: Place the LEONATM 1700S matrix resin in a drying oven and dry it at 80°C for 10 hours. Test the water content of the LEONATM 1700S, which is required to be <0.05%;

[0095] 2) Material mixing: weigh LEONATM 1700S, heat stabilizer CuI / KI, antioxidant 1098, flow modifier CYD-816A, lubricant PTFE powder L-5F, and anti-hydrolysis agent polycarbodiimide according to the formula ratio, add them into the mixer and mix them for 15 minutes;

[0096] 3) Add the mixed material to the twin-screw extruder, adjust the screw temperature and speed, and perform blending modification. Control the pelletizer speed and control the particle size of the modified masterbatch to 5 mm.

[0097] The worm gear forming process is as follows:

[0098] Preheating of metal inserts: Use ultrasonic cleaning equipment to clean the oil, metal powder and impurities on the surface of the metal inserts. Add water-based cleaning agent and rust inhibitor to the cleaning liquid. Clean for 15 minutes and dry. Then preheat the cleaned metal inserts in a heat oven at 100°C for ≥2 hours.

[0099] Drying of matrix resin material: Use a mixer to mix LEONATM 1702 and modified masterbatch in proportion, place in a drying oven for drying at 80°C for 10 hours, test the water content of the mixture, and the requirement is <0.05%;

[0100] Injection molding: add the dried base resin and modified masterbatch mixture into the injection molding machine hopper, put the preheated metal insert into the mold, the mold temperature is 80℃, the injection molding machine uses a 230T machine, the screw temperature is 290℃, 280℃, 280℃, 270℃, 270℃, the hot runner temperature is set to 235℃, the injection pressure is 160, the injection time is 35s, the holding pressure is 160, 130, 90, and the holding time is 20s, 10s, 5s.

[0101] Demolding: After demolding, the injection molded product is placed in an environment of 80°C and slowly cooled;

[0102] Post-processing: Place the cooled injection molded product in an 80°C oven for post-processing for 10 hours to remove internal stress and prevent cracking of the injection molded product during processing and transportation;

[0103] Processing: According to the requirements of the drawings, the injection molded products are processed by CNC lathe (refer to the structural diagram Figure 5 ), get the EPS worm gear (refer to the structural diagram Figure 1 ), where α=30 degrees, β=45 degrees, and W=2 mm.

[0104] Example 2

[0105] The composite material formula is as follows:

[0106]

[0107] EPS worm gear preparation process:

[0108] (1) Modified masterbatch preparation process:

[0109] 1) Drying of PA66 matrix resin: The S240C matrix resin was placed in a drying oven and dried at 80°C for 10 hours. The water content of S240C is required to be less than 0.05%;

[0110] 2) Material mixing: Mix Ascend 67B, heat stabilizer CuI / KI, antioxidant 245, flow modifier H30P, calcium stearate, anti-hydrolysis agent polycarbodiimide were weighed according to the formula ratio, added into the mixer and mixed for 10 minutes;

[0111] 3) Add the mixed material to the twin-screw extruder, adjust the screw temperature and speed, and perform blending modification. Control the pelletizer speed and the masterbatch particle size to 3mm.

[0112] EPS worm gear molding process

[0113] Preheating of metal inserts: Use ultrasonic cleaning equipment to clean the oil, metal powder and impurities on the surface of the metal inserts. Add water-based cleaning agent and rust inhibitor to the cleaning liquid. Clean for 15 minutes and dry. Then preheat the cleaned metal inserts in a heat oven at 100°C for ≥2 hours.

[0114] Mixed material drying: Use a mixer to mix Ascend 67B and modified masterbatch were mixed evenly according to the proportion, placed in a drying oven for drying at 120°C for 4 hours, and the water content of the mixture of the base resin and modified masterbatch was tested, which was required to be <0.05%;

[0115] EPS worm gear injection molding: add the dried base resin and modified masterbatch mixture into the injection molding machine hopper, put the preheated metal insert into the mold, the mold temperature is 120℃, the injection molding machine uses a 160T machine, the screw temperature is 290℃, 280℃, 280℃, 270℃, 270℃, the hot runner temperature is set to 235℃, the injection pressure is 140, the injection time is 30s, the holding pressure is 140, 110, 90, and the holding time is 18s, 12s, 5s.

[0116] Demolding: After the EPS worm wheel blank is demoulded, it is placed in an 80℃ environment for slow cooling to avoid rapid cooling of the EPS worm wheel blank, which may cause cracking.

[0117] Post-processing: Place the cooled EPS worm wheel blank in an 80℃ oven for post-processing for 12 hours to remove the internal stress of the EPS worm wheel blank and avoid cracking of the EPS worm wheel blank during processing and transportation;

[0118] Processing: According to the requirements of the drawing, the EPS worm gear blank is processed by a CNC lathe to obtain the EPS worm gear, where α=35 degrees, β=45 degrees, and W=1.5 mm.

[0119] Example 3

[0120] A masterbatch and an EPS worm gear were obtained in a similar manner to Example 1, except that the CuI / KI in the masterbatch formula was reduced to 3 parts by weight and the antioxidant 1098 was reduced to 3 parts by weight.

[0121] Example 4

[0122] A masterbatch and an EPS worm gear were obtained in a similar manner to Example 1, except that the CuI / KI in the masterbatch formula was increased to 8 parts by weight and the antioxidant 1098 was increased to 8 parts by weight.

[0123] Example 5

[0124] A masterbatch and an EPS worm gear were obtained in a similar manner to Example 1, except that CYD in the masterbatch formula was increased to 8 parts by weight.

[0125] Example 6

[0126] A masterbatch and an EPS worm gear were obtained in a similar manner to Example 1, except that L-5F in the masterbatch formula was increased to 8 parts by weight.

[0127] Example 7

[0128] A masterbatch and an EPS worm gear were obtained in a similar manner to Example 1, except that the polycarbodiimide in the masterbatch formulation was increased to 6 parts by weight.

[0129] Example 8

[0130] A masterbatch and an EPS worm gear were obtained in a similar manner to Example 1, except that the polycarbodiimide in the masterbatch formula was reduced to 0 parts by weight.

[0131] Example 9

[0132] The masterbatch and EPS worm gear were obtained in a similar manner as in Example 2, except that Ascend 67B and For S240C TW341B replacement.

[0133] Example 10

[0134] The masterbatch and EPS worm gear were obtained in a similar manner as in Example 2, except that Ascend 67B and S240C is replaced with MX nylon S6121.

[0135] Embodiment 11

[0136] The masterbatch and EPS worm gear were obtained in a similar manner as in Example 2, except that Ascend 67B and S240C is replaced by VICTREX PEEK 450G.

[0137] Comparative Example 1

[0138] The EPS worm gear was obtained in a similar manner as in Example 2, except that No modified masterbatch is added to 67B.

[0139] Composite material performance test:

[0140] 1. The tensile properties test is carried out in accordance with GB / T 1040.2-2022. Type 1A specimens are prepared at a test rate of 50 mm / min and a universal testing machine is used for the test.

[0141] 2. Impact performance test is in accordance with GB / T 1843-2008, the sample size is (80±2.0)mm×(10±0.2)

[0142] mm×(4±0.2)mm, the notch is A-type notch, and the cantilever beam impact testing machine is used for testing.

[0143] EPS worm gear performance test:

[0144] 1. The test of the pressure-release force between metal inserts and composite parts uses a test fixture to fix the worm wheel, and uses a universal testing machine to apply pressure to the metal insert to press the metal insert out of the worm wheel blank. The magnitude of the pressure-release force is recorded. The pressure application rate is 5mm / min. The schematic diagram of the test fixture for the pressure-release force between metal inserts and composite parts is as follows Figure 6 shown.

[0145] 2. The torque test between the metal insert and the composite part is to first process the torque test sample according to the drawing, then use the test fixture to fix the worm wheel blank, use the torque wrench to apply torque on the central axis, so that the metal insert and the composite part are broken and separated, and the torque size is recorded. The torque test fixture is as follows: Figure 7 shown.

[0146] The test results are shown in Table 1 below:

[0147] Table 1

[0148]

[0149]

[0150] Note: “-” indicates that there are pores or cracks inside the injection molded worm gear and the performance test has not been carried out.

[0151] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0152] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0153] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0154] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0155] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0156] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A modified masterbatch for vehicle steering worm gear, characterized in that: include: 3 to 8 parts by weight of heat stabilizer; 3 to 8 parts by weight of antioxidant; 5 to 10 parts by weight of flow modifier; 5 to 10 parts by weight of lubricant; 3 to 8 parts by weight of anti-hydrolysis agent.

2. The modified masterbatch according to claim 1, characterized in that Also includes: The base resin is 56 to 81 parts by weight.

3. The modified masterbatch according to claim 2, characterized in that: The base resin satisfies at least one of the following conditions: Relative viscosity ≥4.8; Viscosity number ≥280.

4. The modified masterbatch according to claim 2, characterized in that: The matrix resin includes at least one of PA66, PA46, semi-aromatic nylon and PEEk.

5. The modified masterbatch according to claim 4, characterized in that: The PA66 includes LEONATM 1702, LEONATM 1700S, RADILON A 50HSKB, S240C, A5H、Ascend At least one of 67B.

6. The modified masterbatch according to any one of claims 1 to 5, characterized in that Satisfy at least one of the following conditions: The thermal stabilizer includes at least one of an alkali metal halide and a cuprous halide; The antioxidant comprises at least one of a hindered phenol antioxidant, a phosphite antioxidant and a hindered amine antioxidant; The flow modifier comprises at least one of an ultra-high molecular weight silicone polymer, a hyperbranched polyester, a hyperbranched polymer, and a dendritic polymer; The lubricant includes at least one of polytetrafluoroethylene powder, molybdenum disulfide powder, graphite powder, fatty acids and their esters, fatty acid amides, metal soaps and alkane lubricants; The anti-hydrolysis agent includes at least one of polycarbodiimide and carbodiimide compounds.

7. The modified masterbatch according to claim 6, characterized in that: Satisfy at least one of the following conditions: The thermal stabilizer comprises a mixture of the alkali metal halide and the cuprous halide in a mass ratio of 1:1 to 10:1; The alkali metal halide includes at least one of potassium iodide and potassium bromide; The cuprous halide comprises at least one of cuprous iodide and cuprous chloride; The antioxidant includes at least one of 1010, 1076, 1098, 245, 168, 626, DNP, DLTP, TNP, TPP, and MB; The flow modifier includes at least one of CYD-816A, CYD-817, CYD-818, CYD-819, H20P, H30P, and H40P; The lubricant includes at least one of polytetrafluoroethylene powder with a particle size of 1 μm to 10 μm, molybdenum disulfide powder with a particle size of 50 μm to 100 μm, graphite powder with a particle size of 1 μm to 50 μm, silicone powder, polyethylene wax, montan wax, amide wax, vinyl bisstearamide, calcium stearate, zinc stearate, sodium stearate and barium stearate.

8. The modified masterbatch according to claim 1, characterized in that: The particle size of the modified masterbatch is 3 mm to 5 mm.

9. A method for preparing the modified masterbatch according to any one of claims 1 to 8, characterized in that: include: Mixing the raw materials of the modified masterbatch to obtain a raw material mixture; The raw material mixture is granulated to obtain the modified masterbatch.

10. The method according to claim 9, characterized in that The raw material mixture contains a base resin, and the water content of the base resin is less than 0.05%.

11. A composite material for a vehicle steering worm gear, characterized in that: include: 94 to 97 parts by weight of base resin; 3 to 6 parts by weight of the modified masterbatch according to any one of claims 1 to 8.

12. The composite material according to claim 11, characterized in that Based on the total mass of the composite material, the content of copper element in the composite material is ≥100 ppm.

13. A method for preparing the composite material according to claim 11 or 12, characterized in that: include: The composite material is obtained by mixing the modified masterbatch according to any one of claims 1 to 7 and a matrix resin, and injecting the obtained mixture.

14. A vehicle steering worm gear, characterized in that: include: Metal inserts; A composite material piece, wherein the composite material piece wraps the edge of the metal insert, and the composite material piece comprises the composite material according to claim 11 or 12.

15. The vehicle steering worm gear according to claim 14, characterized in that: The metal insert comprises: Inner circle; An outer ring, the outer ring is embedded in the composite material piece, and a plurality of spur teeth arranged at intervals along the circumference of the outer ring are provided on the side of the outer ring away from the inner ring, and the spur teeth are located in the middle of the composite material piece in the thickness direction; A connecting portion is connected between the inner ring and the outer ring.

16. The vehicle steering worm gear according to claim 15, characterized in that: The metal insert has a first side and a second side opposite to each other in the thickness direction, the outer ring protrudes toward the second side relative to the connecting portion, and the distance between the surface of the inner ring facing the first side and the surface of the connecting portion facing the first side is 1 mm to 3 mm.

17. The vehicle steering worm gear according to claim 15, characterized in that: The surface of the inner ring facing the first side is connected to the surface of the connecting portion facing the first side through an inclined surface.

18. The vehicle steering worm gear according to claim 17, characterized in that: The acute angle between the inclined surface and the surface of the inner ring facing the first side is 15° to 60°.

19. A method for preparing a vehicle steering worm gear according to any one of claims 14 to 18, characterized in that: include: Preheating the metal insert to obtain a preheated metal insert; Placing the preheated metal insert in an injection mold, and injecting a mixture of the modified masterbatch according to any one of claims 1 to 8 and a matrix resin into the injection mold to form a composite material on at least a portion of the surface of the metal insert to obtain an injection molded product; The injection-molded product is processed to remove a portion of the composite material to obtain the vehicle steering worm gear.

20. The method according to claim 19, characterized in that The step of injecting the mixture of the modified masterbatch according to any one of claims 1 to 8 and the matrix resin into the injection mold comprises: The mixture is injected into the injection mold, and then demolded. The injection molded product obtained after demolding is placed at a temperature of 40° C. to 80° C. for cooling.

21. The method according to claim 20, characterized in that After the cooling, the injection molded product is kept at a temperature of 60° C. to 100° C. for 6 h to 12 h.

22. A vehicle steering gear, characterized in that: A vehicle steering worm gear comprising the vehicle steering worm gear according to any one of claims 14 to 18.

23. A vehicle, characterized in that: It comprises the vehicle steering worm gear according to any one of claims 14 to 18 or the vehicle steering gear according to claim 22.

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