A subframe bushing assembly and method of making the same

Abstract

This invention discloses a subframe bushing assembly and its manufacturing method, comprising: a subframe body, wherein bushing mounting seats are provided at each of the four corners of the subframe body, and a bushing body is disposed inside the bushing mounting seats; the bushing body includes an outer skeleton that matches the mounting holes of the bushing mounting seats; an inner skeleton is disposed inside the outer skeleton, and a rubber elastomer is disposed between the inner skeleton and the outer skeleton; the rubber elastomer is fixedly connected to the inner skeleton and the outer skeleton by a high-temperature vulcanization process. This invention achieves good vibration isolation and load transfer through a multi-layer composite structure of the inner and outer skeletons and the rubber elastomer. The damping cavity on the surface of the outer skeleton increases the rubber deformation space, improving buffering and damping performance; the metal inner core and the inner skeleton are connected by threads for easy assembly and adjustment; the keyway design ensures torque transmission; and the metal base enhances the connection strength between the outer skeleton and the mounting seats.

Description

Technical Field

[0001] This invention relates to the field of subframe bushing technology, and more specifically to a subframe bushing assembly and its manufacturing method. Background Technology

[0002] The subframe bushing assembly is a key elastic connection element in the automotive chassis system, linking the subframe to the body or other components. Its main functions are cushioning, vibration isolation, and limiting. During vehicle operation, uneven road surfaces generate various vibrations and impacts. The subframe bushing assembly effectively absorbs and attenuates these vibrations, reducing the vibrations and noise transmitted to the vehicle body and improving ride comfort. Simultaneously, it restricts the relative movement of the subframe, ensuring vehicle handling stability and precision, and guaranteeing vehicle safety and reliability during operation.

[0003] Traditional subframe bushings suffer from poor adhesion between rubber and metal, and imperfect vulcanization processes, leading to insufficient cross-linking of rubber molecules, easy aging and cracking, and short lifespan. Therefore, a new technical solution is needed to address this issue. Summary of the Invention

[0004] The purpose of this invention is to provide a subframe bushing assembly and its preparation method, which solves the problems of traditional subframe bushings, such as poor bonding between rubber and metal, imperfect vulcanization process, which easily lead to insufficient cross-linking of rubber molecules, easy aging and cracking, and short service life.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a subframe bushing assembly and its manufacturing method, comprising: a subframe body, wherein bushing mounting seats are provided at each of the four corners of the subframe body and a bushing body is provided inside the bushing mounting seats, the bushing body includes an outer skeleton that matches the mounting holes of the bushing mounting seats, an inner skeleton is provided inside the outer skeleton and a rubber elastomer is provided between the inner skeleton and the outer skeleton, the rubber elastomer is fixedly connected to the inner skeleton and the outer skeleton by a high-temperature vulcanization process, a metal inner core is provided inside the inner skeleton and is threadedly connected to the inner skeleton, a keyway is provided inside the metal inner core, and a metal base is provided at the bottom of the outer skeleton and the outer skeleton is fixedly connected to the bushing mounting seats through the metal base.

[0006] In a preferred embodiment of the present invention, a dust cover is provided at the top connection between the metal inner core and the inner frame.

[0007] In a preferred embodiment of the present invention, the top of the outer frame is provided with an end cap, and the end cap covers the surface of the dust cover.

[0008] In a preferred embodiment of the present invention, the surface of the exoskeleton is provided with a plurality of sets of rectangular damping cavities.

[0009] In a preferred embodiment of the present invention, the method for preparing the subframe bushing assembly includes the following steps: Step 1: The inner skeleton is machined, including turning the internal threads and grinding and polishing the outside. After degreasing, washing, phosphating, washing and drying are performed. After the outer skeleton is injection molded, the stamping oil and oxide scale are removed. After pretreatment, the surface of the skeleton is free of sharp corners and burrs to avoid scratching the rubber during vulcanization. Step 2: Mix the NR / NBR blend rubber at a ratio of 7:3, taking into account both vibration damping and oil resistance, and put it into an internal mixer. Add carbon black, plasticizer, vulcanizing agent and accelerator in sequence. After mixing evenly, extrude the mixture into sheets. Press the compound rubber into a rubber blank that matches the mold cavity through a two-roll mill. The rubber blank should be free of bubbles, impurities and missing material. Step 3: Use the dip coating method to immerse the pretreated inner skeleton and outer skeleton into the rubber adhesive, ensuring that the bonding surface of the skeleton is fully coated without any missed coating or glue residue; place the coated skeleton in a hot air drying oven and dry it in two stages to remove the solvent in the adhesive and form a stable adhesive layer. Step 4: Place the dried inner and outer skeletons into the vulcanization mold cavity, put in the rubber blank, insert the detachable oil cavity core, close the mold and lock it; send the mold into the vulcanization molding machine, apply temperature and pressure according to the process parameters to complete the vulcanization crosslinking and bonding of rubber and metal skeleton; after vulcanization is completed, open the mold and take out the bushing blank. Step 5: Insert the metal inner core into the inner skeleton of the bushing blank. The metal inner core is provided with an external thread that matches the internal thread of the inner skeleton. Rotate to the bottom of the inner skeleton and install a sealing cap and an end cap on the top of the inner skeleton. Use a press fitting machine to cold press and assemble the end cap into the end cap slot of the outer skeleton to ensure that the end cap fits the bushing end face without gaps. In a preferred embodiment of the present invention, the alkaline degreasing temperature in step 1 is 80-90°C, the time is 10-15 min, the water washing is done at room temperature for 2-3 min, the zinc phosphating temperature is 55-60°C, the time is 8-10 min, the phosphating film thickness is 5-8 μm, the drying temperature is 100-110°C, and the drying time is 15-20 min.

[0010] In a preferred embodiment of the present invention, the vulcanization temperature in step 4 is 150±2℃, the vulcanization pressure is 15~20MPa, and the vulcanization time is 3~5min / mmm.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides bushing mounting seats at each of the four corners of the subframe body, with a bushing body inside each mounting seat. The bushing body includes an outer frame that matches the mounting holes of the bushing mounting seats. An inner frame is located inside the outer frame, and a rubber elastomer is positioned between the inner and outer frames. The rubber elastomer is fixedly connected to the inner and outer frames via a high-temperature vulcanization process. A metal inner core is located inside the inner frame and is threadedly connected to it. A keyway is located inside the metal inner core. A metal base is located at the bottom of the outer frame, and the outer frame is connected to the bushing mounting seats via the metal base. The fixed connection, through a multi-layered composite structure of inner and outer skeletons and rubber elastomers, achieves excellent vibration isolation and load transfer. The damping cavity on the surface of the outer skeleton increases the deformation space of the rubber, improving buffering and damping performance. The metal inner core and inner skeleton are connected by threads for easy assembly and adjustment, and the keyway design ensures torque transmission. The metal base enhances the connection strength between the outer skeleton and the mounting base. NR / NBR blended rubber is selected to balance vibration reduction and oil resistance, adapting to the complex working conditions of automotive chassis. Through refined pretreatment and segmented vulcanization processes, the rubber and metal skeleton are firmly bonded, avoiding rubber damage or insufficient cross-linking. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the bushing body structure of the present invention. Figure 3 This is a schematic diagram of the bushing body of the present invention from another angle.

[0013] In the diagram: 1. Subframe body; 2. Bushing mounting base; 3. Bushing body; 4. Outer frame; 5. Metal base; 6. Metal inner core; 7. Keyway; 8. End cap; 9. Sealing cap; 10. Damping cavity. Detailed Implementation

[0014] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] Please see Figure 1-3This invention provides a technical solution: a subframe bushing assembly and its manufacturing method, comprising: a subframe body 1, wherein bushing mounting seats 2 are provided at each of the four corners of the subframe body 1, and a bushing body 3 is provided inside the bushing mounting seats 2; the bushing body 3 includes an outer frame 4 that matches the mounting holes of the bushing mounting seats 2; an inner frame is provided inside the outer frame 4, and a rubber elastomer is provided between the inner frame and the outer frame 4; the rubber elastomer is fixedly connected to the inner frame and the outer frame 4 by a high-temperature vulcanization process; a metal inner core 6 is provided inside the inner frame and is threadedly connected to the inner frame; a keyway 7 is provided inside the metal inner core 6; a metal base 5 is provided at the bottom of the outer frame 4, and the outer frame 4 is fixedly connected to the bushing mounting seats 2 through the metal base 5; bushing mounting seats 2 are provided at each of the four corners of the subframe body 1, and a bushing body 3 is provided inside the bushing mounting seats 2; the bushing body 3 includes an outer frame 4 that matches the mounting holes of the bushing mounting seats 2; and a rubber elastomer is provided inside the outer frame 4. An inner skeleton is provided, and a rubber elastomer is placed between the inner skeleton and the outer skeleton 4. The rubber elastomer is fixedly connected to the inner skeleton and the outer skeleton 4 through a high-temperature vulcanization process. A metal inner core 6 is set inside the inner skeleton and is threadedly connected to the inner skeleton. A keyway 7 is set inside the metal inner core 6. A metal base 5 is set at the bottom of the outer skeleton 4, and the outer skeleton 4 is fixedly connected to the bushing mounting seat 2 through the metal base 5. Through the multi-layer composite structure of the inner and outer skeletons 4 and the rubber elastomer, good vibration isolation and load transfer are achieved. The damping cavity 10 on the surface of the outer skeleton 4 can increase the rubber deformation space and improve the buffering and damping performance. The metal inner core 6 is threadedly connected to the inner skeleton for easy assembly and adjustment. The keyway 7 design ensures torque transmission. The metal base 5 enhances the connection strength between the outer skeleton 4 and the mounting seat. NR / NBR blend rubber is selected to balance vibration reduction and oil resistance, adapting to the complex working conditions of the automotive chassis. Through fine pretreatment and segmented vulcanization process, the rubber and metal skeleton are firmly bonded, avoiding rubber damage or insufficient cross-linking.

[0016] Further improvements, such as Figure 2 As shown: A dust cover 9 is provided at the top connection between the metal inner core 6 and the inner frame. The dust cover 9 can effectively prevent dust, mud and other impurities from entering the connection between the inner frame and the metal inner core 6, reduce wear and corrosion, and extend the service life of the bushing assembly.

[0017] Further improvements, such as Figure 2 As shown: The top of the outer frame 4 is provided with an end cap 8, which covers the surface of the dust cover 9. The end cap 8 further enhances the dustproof effect and protects the dust cover 9 from damage by the external environment, ensuring that the dust cover 9 works effectively for a long time.

[0018] Further improvements, such as Figure 3As shown: The surface of the outer frame 4 is provided with several sets of rectangular damping cavities 10, which improve the buffering and damping performance of the bushing assembly.

[0019] A further improved method for manufacturing the subframe bushing assembly includes the following steps: Step 1: The inner skeleton is machined, including turning the internal threads and grinding and polishing the outside. After degreasing, washing, phosphating, washing and drying are performed. After the outer skeleton is injection molded, the stamping oil and oxide scale are removed. After pretreatment, the surface of the skeleton is free of sharp corners and burrs to avoid scratching the rubber during vulcanization. Step 2: Mix the NR / NBR blend rubber at a ratio of 7:3, taking into account both vibration damping and oil resistance, and put it into an internal mixer. Add carbon black, plasticizer, vulcanizing agent and accelerator in sequence. After mixing evenly, extrude the mixture into sheets. Press the compound rubber into a rubber blank that matches the mold cavity through a two-roll mill. The rubber blank should be free of bubbles, impurities and missing material. Step 3: Use the dip coating method to immerse the pretreated inner skeleton and outer skeleton into the rubber adhesive, ensuring that the bonding surface of the skeleton is fully coated without any missed coating or glue residue; place the coated skeleton in a hot air drying oven and dry it in two stages to remove the solvent in the adhesive and form a stable adhesive layer. Step 4: Place the dried inner and outer skeletons into the vulcanization mold cavity, put in the rubber blank, insert the detachable oil cavity core, close the mold and lock it; send the mold into the vulcanization molding machine, apply temperature and pressure according to the process parameters to complete the vulcanization crosslinking and bonding of rubber and metal skeleton; after vulcanization is completed, open the mold and take out the bushing blank. Step 5: Insert the metal inner core into the inner skeleton of the bushing blank. The metal inner core is provided with an external thread that matches the internal thread of the inner skeleton. Rotate to the bottom of the inner skeleton and install a sealing cap and an end cap on the top of the inner skeleton. Use a press fitting machine to cold press and assemble the end cap into the end cap slot of the outer skeleton to ensure that the end cap fits the bushing end face without gaps. In a further improvement, the alkaline degreasing temperature in step 1 is 80-90℃, the time is 10-15 min, the water rinsing is done at room temperature for 2-3 min, the zinc phosphating temperature is 55-60℃, the time is 8-10 min, the phosphating film thickness is 5-8 μm, the drying temperature is 100-110℃, and the drying time is 15-20 min.

[0020] In a further improvement, the vulcanization temperature in step 4 is 150±2℃, the vulcanization pressure is 15~20MPa, and the vulcanization time is 3~5min / mmm.

[0021] Working principle: Bushing mounting seats 2 are located at each of the four corners of the subframe body 1, and a bushing body 3 is installed inside each bushing mounting seat 2. The bushing body 3 consists of an outer frame 4, an inner frame, a rubber elastomer, a metal inner core 6, and a metal base 5. Through the multi-layered composite structure of the inner and outer frames 4 and the rubber elastomer, good vibration isolation and load transfer are achieved. The metal base 5 enhances the connection strength between the outer frame 4 and the mounting seat, ensuring the stability and reliability of the bushing assembly during vehicle operation.

[0022] NR / NBR blends are selected to balance vibration damping and oil resistance. The blend is fed into an internal mixer, with carbon black, plasticizer, vulcanizing agent, and accelerator added sequentially. After thorough mixing, the mixture is sheeted. The compound is then pressed into a preform using a two-roll mill to match the mold cavity.

[0023] The pretreated inner and outer skeletons 4 are immersed in rubber adhesive using a dip-coating method, ensuring full coating of the bonding surfaces. The coated skeletons are then placed in a hot air drying oven for two-stage drying to remove solvent from the adhesive and form a stable adhesive layer. The dried skeletons are then placed in the vulcanizing mold cavity, a rubber blank is placed inside, a detachable oil-filled core is inserted, and the mold is closed and locked. The mold is then fed into a vulcanizing molding machine, where temperature and pressure are applied according to the process parameters to complete the vulcanization, cross-linking, and bonding of the rubber and metal skeleton.

[0024] Through refined pretreatment and segmented vulcanization processes, the rubber is firmly bonded to the metal skeleton, avoiding rubber damage or insufficient cross-linking, thereby improving the durability and performance stability of the bushing assembly.

[0025] The metal inner core 6 is inserted into the inner skeleton of the bushing blank. The metal inner core 6 has external threads that match the internal threads of the inner skeleton, and is rotated to the bottom of the inner skeleton. A sealing cap and end cap 8 are installed on the top of the inner skeleton, and are assembled by cold pressing using a press fitting machine. The end cap 8 is pressed into the end cap 8 slot of the outer skeleton 4, ensuring that the end cap 8 fits snugly against the bushing end face without gaps. The metal inner core 6 and the inner skeleton are connected by threads, which facilitates assembly and adjustment. The keyway 7 design ensures torque transmission. The installation of the sealing cap and end cap 8 further enhances the dustproof and sealing performance of the bushing assembly, improving the stability and reliability of the overall structure.

[0026] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0027] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can refer to mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc., are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change.

[0028] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A subframe bushing assembly, characterized in that: include: The subframe body (1) has bushing mounting seats (2) at each of its four corners and bushing bodies (3) inside the bushing mounting seats (2). The bushing bodies (3) include an outer frame (4) that matches the mounting holes of the bushing mounting seats (2). An inner frame is provided inside the outer frame (4) and a rubber elastomer is provided between the inner frame and the outer frame (4). The rubber elastomer is fixedly connected to the inner frame and the outer frame (4) through a high-temperature vulcanization process. A metal inner core (6) is provided inside the inner frame and is threadedly connected to the inner frame. A keyway (7) is provided inside the metal inner core (6). A metal base (5) is provided at the bottom of the outer frame (4) and the outer frame (4) is fixedly connected to the bushing mounting seats (2) through the metal base (5).

2. The subframe bushing assembly according to claim 1, characterized in that: A dust cover (9) is provided at the top connection between the metal inner core (6) and the inner frame.

3. A subframe bushing assembly according to claim 1, characterized in that: The top of the outer frame (4) is provided with an end cap (8) and the end cap (8) covers the surface of the dust cover (9).

4. A subframe bushing assembly according to claim 1, characterized in that: The surface of the outer frame (4) is provided with several sets of rectangular damping cavities (10).

5. The method for manufacturing a subframe bushing assembly according to claim 1, characterized in that: The method for preparing the subframe bushing assembly includes the following steps: Step 1: The inner skeleton is machined, including turning the internal threads and grinding and polishing the outside. After degreasing, washing, phosphating, washing and drying are performed. After the outer skeleton is injection molded, the stamping oil and oxide scale are removed. After pretreatment, the surface of the skeleton is free of sharp corners and burrs to avoid scratching the rubber during vulcanization. Step 2: Mix the NR / NBR blend rubber at a ratio of 7:3, taking into account both vibration damping and oil resistance, and put it into an internal mixer. Add carbon black, plasticizer, vulcanizing agent and accelerator in sequence. After mixing evenly, extrude the mixture into sheets. Press the compound rubber into a rubber blank that matches the mold cavity through a two-roll mill. The rubber blank should be free of bubbles, impurities and missing material. Step 3: Use the dip coating method to immerse the pretreated inner skeleton and outer skeleton into the rubber adhesive, ensuring that the bonding surface of the skeleton is fully coated without any missed coating or glue residue; place the coated skeleton in a hot air drying oven and dry it in two stages to remove the solvent in the adhesive and form a stable adhesive layer. Step 4: Place the dried inner and outer skeletons into the vulcanization mold cavity, put in the rubber blank, insert the detachable oil cavity core, close the mold and lock it; send the mold into the vulcanization molding machine, apply temperature and pressure according to the process parameters to complete the vulcanization crosslinking and bonding of rubber and metal skeleton; after vulcanization is completed, open the mold and take out the bushing blank. Step 5: Insert the metal inner core into the inner skeleton of the bushing blank. The metal inner core is provided with external threads that match the internal threads of the inner skeleton. Rotate to the bottom of the inner skeleton and install a sealing cap and end cap on the top of the inner skeleton. Use a press fitting machine to cold press and assemble the end cap into the end cap groove of the outer skeleton to ensure that the end cap fits snugly against the end face of the bushing without gaps.

6. The method for manufacturing a subframe bushing assembly according to claim 5, characterized in that: The alkaline degreasing temperature in step 1 is 80-90℃, the time is 10-15 min, the water rinsing is done at room temperature for 2-3 min, the zinc phosphating temperature is 55-60℃, the time is 8-10 min, the phosphating film thickness is 5-8 μm, the drying temperature is 100-110℃, and the drying time is 15-20 min.

7. The method for preparing a subframe bushing assembly according to claim 5, characterized in that: In step 4, the vulcanization temperature is 150±2℃, the vulcanization pressure is 15~20MPa, and the vulcanization time is 3~5min / mmm.

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