Preparation process of a torsion shock absorber for an automobile

Abstract

The present invention discloses a preparation process of a torsion shock absorber for an automobile, which relates to the technical field of production and processing of automobile accessories. Through a series of steps such as turning processing, polyurethane casting, co-molding, thermoplastic molding, cooling and demolding, surface treatment, and nesting treatment, the most optimized preparation process of the polyurethane rubber body is found. While ensuring the elasticity of the polyurethane rubber body, its elongation at break is improved, its resilience performance is improved, and its tear strength is improved. Moreover, through the treatment of the surface of the polyurethane rubber body and the inner surface of the metal collar, the adhesion strength between the two is greatly enhanced, thereby improving the performance of the overall device.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive parts production and processing, and particularly to a preparation process of a torsion shock absorber for automobiles. Background Art

[0002] The torsion shock absorber for automobiles is a commonly used part in automobiles. When an automobile starts, stops, or turns, certain accelerations will be generated. A torsion shock absorber needs to be connected between different connecting mechanisms to buffer these accelerations.

[0003] The existing invention patent with the publication number CN104963979A discloses a torsion rubber core, which includes a torsion rubber core shaft, rubber pads, and a fastening sleeve. It also includes an elastic sheet sleeved on the torsion rubber core shaft, and a support portion is formed on the elastic sheet. The rubber pad includes a first rubber pad and a second rubber pad respectively arranged on both sides of the support portion. The two end faces of the first rubber pad along the axial direction are respectively set as a first pressing surface and a first supporting surface, and the two end faces of the second rubber pad along the axial direction are respectively set as a second pressing surface and a second supporting surface. The first supporting surface and the second supporting surface correspondingly press against the support portion, and both the first rubber pad and the second rubber pad are tightly sleeved on the torsion rubber core shaft. In this way, by arranging the elastic sheet on the torsion rubber core shaft, the elastic sheet cooperates with the first rubber pad and the second rubber pad to play a better shock absorption and buffering role. At the same time, the elastic sheet can further limit the movement of the first rubber pad and the second rubber pad to a certain extent, ensuring the stability of the entire rubber pad and improving the anti-torsion ability of the entire torsion rubber core.

[0004] In addition, the invention patent with the publication number CN107309617A discloses an engine torsion speed-up device and its key component manufacturing process, which includes a regulating valve assembly, a air filtering assembly, and an air intake assembly. The air filtering assembly is connected to the air intake assembly, and the regulating valve assembly is also connected to the air intake assembly. The air filtering assembly is provided with an air filter, a rubber sealing connection plug, and an air filter nozzle, which are connected in series in sequence. The regulating valve assembly includes a fixed housing, a linkage compensation assembly, a sealing assembly, and a valve. The fixed housing is connected to the torsion speed-up device valve seat arranged on the air intake assembly and accommodates and installs the linkage compensation assembly and the sealing assembly. One end of the linkage compensation assembly is connected to the air hole passage arranged on the torsion speed-up device valve seat through the valve, and the other end exposes the fixed housing and can be linked with the vehicle accelerator pedal. The air filter nozzle is communicated with the through hole arranged on the regulating valve assembly through the passage hole arranged on the torsion speed-up device valve seat to the valve.

[0005] The above-mentioned many technical solutions solve the production and preparation of the torsion device, but they do not give a detailed description of the rubber material used, do not give the specific preparation and processing means of the rubber material, and do not make a detailed description of how the rubber material combines with the metal material and how to enhance the adhesion between the two. Summary of the Invention

[0006] In view of the above technical problems, the object of the present invention is to provide a preparation process for a torsion shock absorber for automobiles. Through a series of steps such as turning, polyurethane casting, co-molding, thermoplastics, cooling and demolding, surface treatment, and nesting treatment, the most optimized preparation process of the polyurethane rubber body is found. While ensuring the elasticity of the polyurethane rubber body, its elongation at break is increased, its resilience performance is improved, and its tear strength is improved. Moreover, through the treatment of the surface of the polyurethane rubber body and the inner surface of the metal collar, the bonding strength between the two is greatly enhanced, thereby improving the service performance of the overall device.

[0007] The above technical object of the present invention is achieved through the following technical solutions:

[0008] A preparation process for a torsion shock absorber for automobiles, and the torsion shock absorber for automobiles is obtained through the following operation steps: Step 1, take a metal bar and turn it into a rod core; Step 2, heat the polyurethane to a viscous flow state, then inject it into a half-shell mold, and then cool it to its viscous flow temperature; Step 3, splice two half-shell molds carrying the viscous flow state polyurethane to the center of the rod core; Step 4, heat the polyurethane in Step 3 above its viscous flow temperature; Step 5, cool the polyurethane in Step 4 below its viscous flow temperature, and then remove the half-shell mold to obtain a polyurethane rubber body; Step 6, roughen the inner surface of the metal collar, treat the surface of the polyurethane rubber body with a surface treatment agent, and then spray an adhesive on the surface of the polyurethane rubber body; Step 7, nest the metal collar onto the surface of the polyurethane rubber body.

[0009] By adopting the above technical solutions, this solution uses polyurethane rubber material. Polyurethane rubber has the advantages of high insulation, strong corrosion resistance, low mass density, high production efficiency, good weather resistance, and low cost. The above process finds the most optimized preparation process of the polyurethane rubber body. While ensuring the elasticity of the polyurethane rubber body, its tensile strength and elongation at break are increased, its resilience performance is improved, and its tear strength is improved. Moreover, through the treatment of the surface of the polyurethane rubber body and the inner surface of the metal collar, the bonding strength between the two is greatly enhanced, thereby improving the service performance of the overall device.

[0010] The present invention is further provided as follows: Specifically in Step 1, first take a cylindrical metal bar, and preferably use 306 stainless steel. First, grind, rust-remove, and pickling-treat its surface, then clamp the bar, turn the two ends of the cylindrical metal bar to form a second cut surface, then cut out a first cut surface, and then turn a bar hole in the center of the first cut surface. Finally, hold both ends of the rod core and cut out several disc-shaped ring teeth in the middle of the metal bar.

[0011] By adopting the above technical solution, using stainless steel as the raw material can maintain high strength while controlling costs, and it is not easy to rust, eliminating steps such as surface rust prevention treatment. The function of the rod hole is to provide a part for connecting other parts in the car for the whole device. The function of the ring teeth is to make the rod core and the polyurethane rubber bind more tightly together to ensure that they will not fall off.

[0012] The present invention is further configured as follows: Specifically in step two, first take toluene diisocyanate (TDI) with a mass fraction of 60, 4,4-diphenylmethane diisocyanate (MDI) with a mass fraction of 20, polytetramethylene ether glycol (PTMG) with a mass fraction of 20, and Unilink4200 curing agent with a mass fraction of 4, mix and stir evenly, heat to between 200°C and 230°C, and then inject it into a half-shell mold, and then cool to between 150°C and 170°C. The number-average molecular weight of polytetramethylene ether glycol (PTMG) is between 1000 and 3000, and the Unilink4200 curing agent is a curing agent with 4,4-bis(sec-butylamino)diphenylmethane as the active ingredient.

[0013] By adopting the above technical solution, adding toluene diisocyanate (TDI) and 4,4-diphenylmethane diisocyanate (MDI) in the above proportions and carrying out a chain growth reaction with polytetramethylene ether glycol (PTMG) can adjust the crystal structure inside the polyurethane material, thereby effectively improving the mechanical properties, temperature resistance properties, etc. of the material. Using polytetramethylene ether glycol (PTMG) with a number-average molecular weight of 1000 to 3000 can ensure the polymerization reaction rate of polyurethane while maintaining the tensile properties and resilience properties of the polyurethane rubber. First, heat the polyurethane material to between 200°C and 230°C, then inject it into a half-shell mold, and then cool to between 150°C and 170°C, in order to make it transform from a viscous flow state to a state between a highly elastic state and a viscous flow state, facilitating its subsequent co-molding treatment. The addition of the Unilink4200 curing agent can effectively improve a series of mechanical properties of the polyurethane rubber such as tensile strength, elongation at break, resilience properties, and tear strength. And the Unilink4200 curing agent provides an effective group for the growth of the polyurethane chain, greatly improving the synthesis speed of the polyurethane rubber and improving production efficiency.

[0014] The present invention is further configured as follows: Specifically in step three, within 5 minutes after step two is completed, splice two half-shell molds carrying semi-viscous flow state polyurethane around the central ring teeth of the rod core. The two half-shell molds need to be completely and tightly buckled and located exactly in the center of the rod core. Both of them must completely wrap the ring teeth.

[0015] By adopting the above technical solution, the polyurethane rubber body can be more closely combined with the ring teeth. The traditional method is to pour viscous polyurethane into the entire housing. However, due to the presence of several ring teeth, a lot of bubbles and voids will be generated during the pouring process, which will seriously affect the performance of the torsional damper. The splicing method can well avoid the generation of bubbles and voids.

[0016] The present invention is further configured as follows: Specifically in step four, the polyurethane after being processed in step three is heated to between 190 °C and 210 °C, and then the half-shell mold is fixed, and the rod core is continuously rotated and maintained in this state for 30 min to 120 min.

[0017] By adopting the above technical solution, further heating to 190 °C to 210 °C can keep the polyurethane in a viscous flow state, which can further make the polyurethane more closely combined with the ring teeth and completely discharge the voids and bubbles. In addition, in the range of 190 °C to 210 °C, the chain growth rate of polyurethane can be effectively increased, and its synthesis efficiency can be accelerated. Fixing the half-shell mold and continuously rotating the rod core can make the ring teeth play the role of a stirring paddle. Continuous stirring helps to improve the stability of polyurethane chain growth. Since the polyurethane fluid is a viscoelastic fluid, as the polyurethane chain grows, the internal mass transfer and heat transfer become more and more difficult. Therefore, stirring must be carried out to ensure the overall uniformity of its synthesis.

[0018] The present invention is further configured as follows: Specifically in step five, the rotation of the rod core is stopped, and the polyurethane after being processed in step four is cooled to between 130 °C and 160 °C and maintained in this state for 5 min to 20 min. Then it is slowly cooled to room temperature at a cooling rate of 1 °C / min to 5 °C / min, and the half-shell mold is removed to obtain the polyurethane rubber body.

[0019] By adopting the above technical solution, stopping the rotation of the rod core and cooling the polyurethane to between 130 °C and 160 °C serves to stop the synthesis of polyurethane. Since the polyurethane chain growth rate becomes slower and slower with the reaction time, and its molecular weight reaches the required level for production. Therefore, timely stopping can achieve the optimal production cost performance. Maintaining at 130 °C to 160 °C and staying for 5 min to 20 min can make the polyurethane effectively fit the half-shell mold and form the required outer shape according to the shape of the half-shell mold. Keeping the cooling rate at 1 °C / min to 5 °C / min can make the polyurethane rubber slowly take shape and prevent the generation of cracks, bubbles, voids, etc. After cooling, due to the volume shrinkage, the half-shell mold can be easily removed.

[0020] The present invention is further configured as follows: Specifically in step six, the material used for the metal collar is 306 stainless steel. The inner surface of the metal collar is contacted with a 20% to 50% nitric acid solution (by mass fraction) at room temperature for 15 min to 40 min, and then the inner surface of the metal collar is cleaned with water; the surface of the polyurethane rubber body is soaked in a hypochlorous acid solution for 40 min to 80 min, and then cleaned with water. After that, the polyurethane rubber body is dried at a temperature between 60°C and 100°C, and then the Chemlok 250 adhesive is evenly applied to the surface of the polyurethane rubber body.

[0021] By adopting the above technical solution, using a 20% to 50% nitric acid solution (by mass fraction) can ensure both the hydrogen ion concentration of the nitric acid solution and its oxidizing property. At room temperature, nitric acid can undergo a slow oxidation reaction with the surface of the metal collar to form a layer of magnetite passivation film. And the room temperature condition can prevent the passivation film from further corrosion by nitric acid. The surface of the passivation film is rough and has a large specific surface area, which is very conducive to the penetration of the adhesive, thereby enhancing its bonding effect with the polyurethane rubber body. Soaking the surface of the polyurethane rubber body with a hypochlorous acid solution can generate a large number of fine cracks on its surface, which helps the penetration of the adhesive. In addition, the strong oxidizing property of hypochlorous acid can add polar groups such as hydroxyl groups, carboxyl groups, and chlorine atoms to the surface of the polyurethane rubber body, which helps the adsorption, wetting, and uniform penetration of the adhesive. Drying at a temperature between 60°C and 100°C can ensure the rapid drying of the surface of the polyurethane rubber body and will not cause adverse chemical reactions on its surface due to excessive temperature. Chemlok 250 adhesive is a widely used adhesive between rubber and metal, with stable performance and low cost.

[0022] The present invention is further configured as follows: Specifically in step seven, within 5 min after the treatment in step six, the metal collar is nested onto the surface of the polyurethane rubber body and maintained in this state for 30 min to 60 min. Then the entire torsional shock absorber for automobiles is completed.

[0023] By adopting the above technical solution, nesting within 5 min is to prevent the adhesive from solidifying and losing its adhesive effect. Maintaining for 30 min to 60 min is to allow the adhesive to fully penetrate into the inner surface of the metal collar and the surface of the polyurethane rubber body, and then have enough time to solidify, making the two bond more tightly.

[0024] In summary, the beneficial technical effects of the present invention are:

[0025] (1) By using a reasonable mass fraction ratio to add toluene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (MDI), polytetramethylene ether glycol (PTMG), and Unilink4200 curing agent as raw materials for polyurethane rubber parts, a series of mechanical properties such as the tensile strength, elongation at break, resilience, and tear strength of the polyurethane rubber are effectively improved. The synthesis speed and production efficiency of the polyurethane rubber are increased;

[0026] (2) By splicing two half-shell molds carrying semi-viscous polyurethane around the central ring teeth of the rod core and completely wrapping the ring teeth, the generation of bubbles and voids between the polyurethane rubber body and the ring teeth can be well avoided;

[0027] (3) By fixing the half-shell mold and continuously rotating the rod core to play a stirring role, the stability of polyurethane chain growth can be improved, the mass transfer and heat transfer efficiency inside it can be enhanced, and the overall uniformity of polyurethane synthesis can be improved;

[0028] (4) By treating the inner surface of the metal collar with nitric acid solution and treating the surface of the polyurethane rubber body with hypochlorous acid solution, a passivation film with rough surface and large specific surface area can be formed on the inner surface of the metal collar, and a large number of fine cracks can be formed on the surface of the polyurethane rubber body, and polar groups are added, so as to achieve the effect of enhancing the adsorption, wetting and uniform penetration of the adhesive, and further improve the adhesive effect between the metal collar and the polyurethane rubber body. Brief Description of the Drawings

[0029] Figure 1 is a schematic process flow diagram of an embodiment of the present invention;

[0030] Figure 2 is a schematic overall structure diagram of an automotive torsion damper prepared according to an embodiment of the present invention;

[0031] Figure 3 is a schematic cross-sectional view of an automotive torsion damper prepared according to an embodiment of the present invention;

[0032] Figure 4 is a schematic structure diagram of the half-shell mold used in an embodiment of the present invention.

[0033] Reference Numerals: 1, rod core; 11, first section plane; 12, second section plane; 13, rod hole; 14, ring teeth; 2, polyurethane rubber body; 200, half-shell mold; 3, metal collar; 4, sealing rubber ring. Detailed Embodiments

[0034] The present invention will be clearly and completely described below in conjunction with the embodiments.

[0035] See the attached Figure 1 and in combination with the attachedFigure 2 、Attachment Figure 3 、Attachment Figure 4 , A preparation process for a torsional shock absorber for automobiles:

[0036] The torsional shock absorber for automobiles provided by the present invention is prepared through the following operating steps:

[0037] Step 1: First, take a cylindrical metal bar, preferably using 306 stainless steel. First, polish, rust-remove, and pickling-treat its surface, then clamp the bar, turn the two ends of the cylindrical metal bar to produce a second cutting surface 12, then cut out a first cutting surface 11, and then turn a bar hole 13 in the center of the first cutting surface 11. Finally, hold both ends of the bar core 1 and cut out several disc-shaped ring teeth 14 in the middle of the metal bar.

[0038] Step 2: First, take toluene diisocyanate (TDI) with a mass fraction of 60, 4,4-diphenylmethane diisocyanate (MDI) with a mass fraction of 20, polytetramethylene ether glycol (PTMG) with a mass fraction of 20, and Unilink4200 curing agent with a mass fraction of 4, mix and stir evenly, heat to 210 °C, then inject it into a half-shell mold 200, and then cool to 160 °C. The number-average molecular weight of polytetramethylene ether glycol (PTMG) is between 1000 and 3000, and the Unilink4200 curing agent is a curing agent with 4,4-bis(sec-butylamino)diphenylmethane as the active ingredient.

[0039] Step 3: Within 5 minutes after Step 2 is completed, splice two half-shell molds 200 carrying semi-viscous polyurethane around the central ring teeth 14 of the bar core 1. The two half-shell molds 200 need to be completely and tightly buckled and located exactly in the center of the bar core 1. Both of them must completely wrap the ring teeth 14.

[0040] Step 4: Heat the polyurethane after being processed in Step 3 to 200 °C, then fix the half-shell mold 200 and rotate the bar core 1 continuously, and maintain this state for 80 minutes.

[0041] Step 5: Stop rotating the bar core 1, cool the polyurethane after being processed in Step 4 to 140 °C, and maintain this state for 15 minutes. Then slowly cool it to room temperature at a cooling rate of 3 °C / min, and remove the half-shell mold 200 to obtain a polyurethane rubber body 2.

[0042] Step 6: The material used for the metal collar 3 is 306 stainless steel. The inner surface of the metal collar 3 is contacted with a 35% nitric acid solution (mass fraction) at room temperature for 25 minutes, and then the inner surface of the metal collar 3 is cleaned with water; the surface of the polyurethane rubber body 2 is soaked in a hypochlorous acid solution for 60 minutes, and then cleaned with water. After that, the polyurethane rubber body 2 is dried at 80 °C, and then the Chemlok 250 adhesive is evenly applied on the surface of the polyurethane rubber body 2.

[0043] Step 7: Within 5 minutes after the treatment in Step 6, the metal collar 3 is nested onto the surface of the polyurethane rubber body 2 and kept in this state for 60 minutes. Then the entire automotive torsion shock absorber is completed.

[0044] The working principle of this embodiment is as follows: Using stainless steel as the raw material can maintain high strength while controlling costs, and it is not easy to rust, eliminating steps such as surface rust prevention treatment. The function of the rod hole 13 is to provide a part for connecting other parts in the vehicle for the entire device. The function of the ring teeth 14 is to enable the rod core 1 and the polyurethane rubber to be more closely combined to ensure that they will not fall off. Adding toluene diisocyanate (TDI) and 4,4-diphenylmethane diisocyanate (MDI) in the above-mentioned ratio and carrying out a chain growth reaction with polytetramethylene ether glycol (PTMG) can adjust the crystal structure inside the polyurethane material, thereby effectively improving the mechanical properties, temperature resistance performance, etc. of the material. Using polytetramethylene ether glycol (PTMG) with a number average molecular weight of 1000 to 3000 can ensure the polymerization reaction rate of polyurethane while maintaining the tensile properties and resilience properties of the polyurethane rubber. First, heat the polyurethane material to 210 °C, then inject it into the half-shell mold 200, and then cool it to 160 °C to make it transform from the viscous flow state to a state between the high elastic state and the viscous flow state, facilitating subsequent mold joining treatment. The addition of Unilink4200 curing agent can effectively improve a series of mechanical properties of the polyurethane rubber, such as tensile strength, elongation at break, resilience performance, tear strength, etc. And the Unilink4200 curing agent provides effective groups for the chain growth of polyurethane, greatly increasing the synthesis speed of the polyurethane rubber and improving production efficiency. The polyurethane rubber body can be more closely combined with the ring teeth 14. The traditional method is to pour viscous flow state polyurethane into the entire shell, but due to the existence of several ring teeth 14, many bubbles and voids will be generated during the pouring process, thus seriously affecting the use performance of the torque shock absorber. The splicing method can well avoid the generation of bubbles and voids. Further heating to 200 °C to keep the polyurethane in the viscous flow state can further make the polyurethane more closely combined with the ring teeth 14 and completely remove voids and bubbles. In addition, at 200 °C, the chain growth rate of polyurethane can be effectively increased, accelerating its synthesis efficiency. Fix the half-shell mold 200 and continuously rotate the rod core 1, which can make the ring teeth 14 play the role of a stirring paddle. Continuous stirring helps to improve the stability of polyurethane chain growth. Since the polyurethane fluid is a viscoelastic fluid, as the chain growth of polyurethane progresses, mass transfer and heat transfer inside it become more and more difficult. Therefore, stirring must be carried out to ensure the overall uniformity of its synthesis.

[0045] Then stop rotating the rod core 1 and cool the polyurethane to 140 °C, which serves to stop the synthesis of polyurethane. Since the growth rate of the polyurethane chain slows down with the reaction time and its molecular weight reaches the required production level, timely stopping can achieve the optimal production cost performance. Maintaining at 140 °C and staying for 15 minutes can enable the polyurethane to effectively adhere to the half-shell mold 200, making it generate the required outer shape according to the shape of the half-shell mold 200. Keeping the cooling rate at 3 °C / min can enable the polyurethane rubber to slowly take shape, preventing the generation of cracks, bubbles, voids, etc. After cooling, due to the volume shrinkage, the half-shell mold 200 can be easily removed. Using a 35% nitric acid solution (mass fraction) can ensure both the hydrogen ion concentration of the nitric acid solution and its oxidizing property. At room temperature, nitric acid can undergo a slow oxidation reaction with the surface of the metal collar to form a layer of magnetite passivation film. And the room temperature condition can protect the passivation film from further corrosion by nitric acid. The surface of the passivation film is rough and has a large specific surface area, which is very conducive to the penetration of the adhesive, thereby enhancing its bonding effect with the polyurethane rubber body 2. Soaking the surface of the polyurethane rubber body 2 with a hypochlorous acid solution can cause a large number of fine cracks to form on its surface, which helps the penetration of the adhesive. In addition, the strong oxidizing property of hypochlorous acid can add polar groups such as hydroxyl groups, carboxyl groups, and chlorine atoms to the surface of the polyurethane rubber body 2, which helps the adsorption, wetting, and uniform penetration of the adhesive. Drying at 80 °C can ensure the rapid drying of the surface of the polyurethane rubber body 2 without causing adverse chemical reactions due to excessive surface temperature. Chemlok250 adhesive is a widely used adhesive between rubber and metal, with stable performance and low cost. Nesting within 5 minutes is to prevent the adhesive from solidifying and losing its adhesive effect. Maintaining for 60 minutes is to allow the adhesive to fully penetrate into the inner surface of the metal collar 3 and the surface of the polyurethane rubber body 2, and then have enough time to solidify, making the two bond more tightly.

[0046] The overall operation steps of this embodiment are as follows: Step 1, take a metal bar and machine it into a rod core 1; Step 2, heat the polyurethane to the viscous flow state, then inject it into the half-shell mold 200, and then cool it to its viscous flow temperature; Step 3, splice two half-shell molds 200 carrying the viscous flow state polyurethane to the center of the rod core 1; Step 4, heat the polyurethane in Step 3 to above its viscous flow temperature; Step 5, cool the polyurethane in Step 4 to below its viscous flow temperature, and then remove the half-shell mold 200 to obtain a polyurethane rubber body; Step 6, roughen the inner surface of the metal collar 3, treat the surface of the polyurethane rubber body 2 with a surface treatment agent, and then spray the adhesive on the surface of the polyurethane rubber body 2; Step 7, nest the metal collar 3 onto the surface of the polyurethane rubber body 2.

[0047] The above are only the preferred specific embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A preparation process for a torsion shock absorber for an automobile, characterized in that: The torsion shock absorber for automobiles is obtained through the following operating steps: Step 1: Take a metal bar and turn it into a rod core (1). The middle of the rod core (1) has several ring teeth (14). Step 2: Heat the polyurethane to the viscous flow state, then inject it into the half-shell mold (200), and then cool it to its viscous flow temperature to make it transform from the viscous flow state to a semi-viscous flow state between the high elastic state and the viscous flow state. Step 3: Splice two half-shell molds (200) carrying the semi-viscous flow state polyurethane around the ring teeth (14) in the center of the rod core (1) and completely wrap the ring teeth (14). Step 4: Heat the polyurethane in Step 3 to above its viscous flow temperature, and then continuously rotate the rod core (1). Step 5: Stop rotating the rod core (1), cool the polyurethane in Step 4 to below its viscous flow temperature, and then remove the half-shell mold (200) to obtain the polyurethane rubber body (2). Step 6: Roughly process the inner surface of the metal collar (3), treat the surface of the polyurethane rubber body (2) with a surface treatment agent, and then spray an adhesive on the surface of the polyurethane rubber body (2). Step 7: Nest the metal collar (3) onto the surface of the polyurethane rubber body (2).

2. The preparation process of the torsion shock absorber for automobiles according to claim 1, characterized in that: In Step 1, first turn the two ends of the cylindrical metal bar to produce a second cutting surface (12), then cut out a first cutting surface (11), then turn a rod hole (13) in the center of the first cutting surface (11), and then cut several ring teeth (14) in the middle of the metal bar.

3. The preparation process of the torsional shock absorber for automobiles according to claim 1, characterized in that: In Step 2, first take toluene diisocyanate (TDI) with a mass fraction of 60, 4,4-diphenylmethane diisocyanate (MDI) with a mass fraction of 20, polytetramethylene ether glycol (PTMG) with a mass fraction of 20, and Unilink4200 curing agent with a mass fraction of 4, mix and stir evenly, then heat it to between 200°C and 230°C, then inject it into the half-shell mold (200), and then cool it to between 150°C and 170°C.

4. The preparation process of the torsion shock absorber for automobiles according to claim 1, characterized in that: In Step 3, within 5 minutes after Step 2 is completed, splice two half-shell molds (200) carrying the semi-viscous flow state polyurethane around the central ring teeth (14) of the rod core (1) and completely wrap the ring teeth (14).

5. The preparation process of the torsion shock absorber for automobiles according to claim 1, characterized in that: In Step 4, heat the polyurethane processed in Step 3 to between 190°C and 210°C, then fix the half-shell mold (200), continuously rotate the rod core (1), and maintain this state for 30 minutes to 120 minutes.

6. The preparation process of the torsion shock absorber for automobiles according to claim 1, characterized in that: In Step 5, stop rotating the rod core (1), cool the polyurethane processed in Step 4 to between 130°C and 160°C, maintain this state for 5 minutes to 20 minutes, then cool it to room temperature, and remove the half-shell mold (200) to obtain the polyurethane rubber body (2).

7. The preparation process of the torsion shock absorber for automobiles according to claim 1, characterized in that: In Step 6, the inner surface of the metal collar (3) is contacted with a 20% to 50% nitric acid solution (mass fraction) at room temperature for 15 min to 40 min, and then the inner surface of the metal collar (3) is cleaned with water; the surface of the polyurethane rubber body (2) is soaked in a hypochlorous acid solution for 40 min to 80 min, and then cleaned with water. After that, the polyurethane rubber body (2) is dried at a temperature between 60 °C and 100 °C, and then the Chemlok 250 adhesive is evenly applied to the surface of the polyurethane rubber body (2).

8. The preparation process of the torsion shock absorber for automobiles according to claim 1, characterized in that: In Step 7, within 5 min after the treatment in Step 6, the metal collar (3) is nested onto the surface of the polyurethane rubber body (2), and this state is maintained for 30 min to 60 min.

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