Vacuum power assisting device and method for automobile braking system

Abstract

The invention discloses a vacuum power assisting device for an automobile braking system, which comprises a spacer bush mounted in the vacuum power assisting device; the spacer bush comprises a bent part located in the middle and installation parts located at the two ends of the bent part, and the bent part is of a sine wave structure. Wedge-shaped sealing structures are arranged at the mounting parts; the composite material spring is installed in the vacuum power assisting device, and the composite material spring is mixed and woven through an annular weaving technology; the composite material spring is more excellent in vibration absorption and noise reduction, the stability of the device is effectively improved, and the service life of the device is effectively prolonged.

Description

Technical Field

[0001] This invention belongs to the field of automotive braking system technology, and relates to a vacuum booster device for passenger vehicles and the optimized design of its key components, specifically a vacuum booster device and method for automotive braking systems. Background Technology

[0002] With the rapid development of new energy vehicle technology, various automotive technologies are constantly iterating, especially the requirements for braking systems are increasing. In the pursuit of lightweighting and high performance, optimizing traditional braking system components has become a pressing issue for the automotive industry. Although vacuum boosters are gradually being replaced in some new energy vehicles, they still play a crucial role in many hybrid and traditional fuel vehicles. Working in conjunction with EPB (Electronic Braking System), they jointly improve the safety and responsiveness of the vehicle during service and parking braking.

[0003] As a core component of the automotive braking system, the vacuum booster amplifies the braking force applied by the driver, improving braking efficiency and safety. The working principle of the vacuum booster is based on the pressure difference within its chambers. Inside the vacuum booster is a large chamber divided into two chambers by a diaphragm. One side of the chamber is connected to the vehicle's vacuum source, forming a vacuum chamber, while the other side is connected to the atmosphere. When the driver depresses the brake pedal, the pressure difference between the left and right chambers pushes a piston inside the vacuum booster, amplifying the braking force applied by the driver and thus improving the efficiency of the entire braking system.

[0004] While vacuum booster devices are widely used in passenger vehicle braking systems, some key components, such as spacers and metal springs, still have limitations. Spacers, with their simple structure, are prone to sealing failure and poor wear resistance during long-term use. Metal springs, on the other hand, are limited by fatigue failure and weight, thus affecting the overall performance and safety of the braking system.

[0005] The vacuum booster unit's spacer is located inside the unit. Its main function is to seal the vacuum chamber to prevent atmospheric entry, thus ensuring the booster operates within a proper vacuum environment. This spacer is positioned between two partitions, helping to isolate the internal vacuum chamber from the external atmosphere. The vacuum booster's springs are specifically located inside the unit. Different types of springs are distributed within the internal controller and chambers. The springs inside the controller primarily regulate the booster's opening and closing actions, while the springs in the chambers are responsible for resetting the piston, ensuring the system quickly returns to its initial state after braking.

[0006] Composite materials possess advantages such as low density, high modulus, and high specific strength, and their corrosion resistance is far superior to traditional metals. They can maintain their performance in harsh environments such as high humidity and salt spray, thereby improving product reliability and reducing maintenance costs. They are excellent lightweight materials for automobiles and have been widely used in new energy vehicles in recent years. Composite material preparation technologies are constantly being innovated, with ring weaving technology demonstrating extremely high design flexibility. This technology can adjust fiber types, weaving angles, and the number of layers according to specific needs, giving products excellent multi-directional load-bearing capacity and adapting to the diverse requirements of new energy vehicles. The lightweight characteristics of composite materials are particularly suitable for electric vehicles, effectively reducing overall vehicle weight, improving vehicle energy efficiency, and meeting the dual requirements of modern automobiles for lightweighting and high performance. Summary of the Invention

[0007] This application addresses the current state of passenger vehicle braking systems by combining ring braiding technology and composite material manufacturing processes to introduce optimized reinforced spacers and hybrid composite springs. This not only reduces overall vehicle weight but also improves energy efficiency and extends driving range. Furthermore, the optimized design enhances the fatigue and corrosion resistance of components, thereby improving the overall performance and safety of the passenger vehicle braking system. It also meets the modern automotive industry's demand for efficient, lightweight, and long-life braking systems, demonstrating broad application prospects.

[0008] To address the above problems, this invention proposes a vacuum booster device for an automotive braking system, comprising:

[0009] A spacer sleeve is installed inside the vacuum booster device; the spacer sleeve includes a bent portion in the middle and mounting portions at both ends of the bent portion, the bent portion having a sinusoidal wave structure; and each mounting portion is provided with a wedge-shaped sealing structure.

[0010] A composite material spring is installed inside the vacuum booster device, and the composite material spring is woven using a ring-shaped weaving technique.

[0011] Furthermore, the spacer includes, from the outside to the inside, an outer layer of rubber, a braided layer, and an inner layer of rubber;

[0012] The wedge-shaped sealing structures at both ends of the spacer, located at their mounting portions, are respectively provided with a first wedge-shaped sealing groove and a second wedge-shaped sealing groove.

[0013] A method for manufacturing a vacuum booster device for an automotive braking system, wherein the manufacturing steps of the spacer include:

[0014] Step 1: Select a metal rod of appropriate diameter according to the requirements and install it on the circular braiding machine;

[0015] Step 2: Cut natural compound rubber sheets to the appropriate size according to requirements, and evenly wind them onto the metal rod in Step 1 to form a complete round tube shape, i.e., the inner layer of the spacer rubber.

[0016] Step 3: Using a circular braiding machine, nylon fibers are evenly and tightly braided at a 45-degree angle onto the inner rubber surface of the spacer in Step 2 to form a braided layer;

[0017] Step 4: Cut natural compound rubber sheets to the appropriate size according to requirements, and evenly wind them onto the braided layer of Step 3, i.e. the outer rubber layer of the spacer, to form a sandwich structure of "rubber-braided layer-rubber".

[0018] Step 5: Demold the sandwich structure from the metal rod in Step 4, trim its surface, and press it into shape using a spacer mold.

[0019] Step 6: Place the spacer mold from Step 5 into the flat vulcanizing machine, set the vulcanization time, temperature, and pressure, and carry out the vulcanization treatment;

[0020] Step 7: Cool the vulcanized spacer mold, remove the vulcanized spacer from the mold, and trim the surface of the spacer to obtain the final product.

[0021] Furthermore, the thickness of the inner rubber layer of the spacer and / or the thickness of the outer rubber layer of the spacer is half the thickness of the spacer.

[0022] Furthermore, in step five, the spacer mold includes an inner mold shaft, an upper mold, and a lower mold; the upper mold and the lower mold are located at the top and bottom of the spacer mold; the inner mold shaft is located between the upper mold and the lower mold and is detachably installed; the spacer mold is provided with an annular wedge-shaped sealing groove adapted to the size of the spacer and an inner cavity with a sine wave structure.

[0023] Furthermore, in step five, the sandwich structure after surface trimming is evenly and tightly wrapped around the inner mold shaft, then placed in the lower mold, and closed by the upper mold.

[0024] Furthermore, the preparation steps of the composite material spring include:

[0025] Step 1: Select a suitable mandrel as the support structure during the weaving process, and select at least two types of fibers to be mixed and woven together using a ring braiding machine; the at least two types of fibers are woven layer by layer until the preset number of weaving layers and thickness are reached to obtain preform A;

[0026] Step 2: Trim the preform A from Step 1 and place it in a vacuum bag. Connect both ends to the guide tube and seal them. Bend one end to seal it, and connect the other end to the vacuum pump to exhaust air, maintaining the vacuum state of the vacuum bag to ensure smooth resin injection.

[0027] Step 3: Mix the resin and curing liquid in proportion and stir thoroughly; put the mixed resin into a vacuum pump to remove the air from the resin, ensuring that the resin is uniform and free of bubbles, to obtain solution a; insert the bent guide tube into solution a, and use the vacuum pump to continuously draw the solution a to evenly penetrate into all areas of preform A, so that it is completely wetted, and finally form preform B.

[0028] Step 4: Wrap the precast component B around the mold cavity of the plaster mandrel, and then press and cure it using a composite material spring metal mold;

[0029] Step 5: After curing and molding, remove the plaster core using the plaster disappearing method, and then polish the demolded composite material spring.

[0030] Furthermore, in step four, the plaster mandrel is made using a plaster mandrel metal mold.

[0031] Furthermore, the curing process of precast component B is as follows:

[0032] S101. Plaster mandrels are made using a plaster mandrel metal mold.

[0033] S102. Wrap the precast part B around the mold cavity of the plaster mandrel;

[0034] S103. The plaster mandrel of the precast component B is closed by a composite material spring metal mold.

[0035] S104. Place the composite material spring metal mold from S103 into the oven, and adjust the oven to the appropriate temperature and time for heating and curing.

[0036] Furthermore, the two types of fibers in step one include carbon fiber and basalt fiber.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) This invention improves the structure of the vacuum booster's sleeve by adopting a "rubber-woven layer-rubber" sandwich structure design and a sinusoidal waveform structure in the sleeve body, significantly enhancing the sleeve's flexibility, wear resistance, and durability. Furthermore, annular wedge-shaped sealing grooves are designed at both ends of the sleeve, effectively improving the sealing performance of the vacuum booster and ensuring operational stability. In addition, compared to traditional metal springs, composite material springs not only significantly reduce weight but also greatly improve the overall performance of the vacuum booster. By combining carbon fiber and basalt fiber in a 45° angle hybrid weave design, the spring possesses excellent fatigue resistance and corrosion resistance, and its elastic modulus can be further optimized by adjusting the fiber arrangement and material selection, thereby enhancing its load response capability. Compared to metal springs, composite material springs perform better in vibration absorption and noise reduction, effectively improving the stability and service life of the device.

[0039] (2) For the rubber spacer, after obtaining the "rubber-woven layer-rubber" sandwich structure based on manual winding process and ring weaving technology, hot-press vulcanization process is adopted to ensure the tight bond between the fiber and the rubber, further improving the wear resistance and durability of the spacer. The spacer mold used is equipped with annular wedge-shaped sealing groove and sinusoidal waveform structure to match the design of the rubber spacer.

[0040] (3) For composite springs, carbon fiber and basalt fiber are mixed and woven at a 45° angle using ring weaving technology. The resulting prefabricated fabric is then completely and uniformly impregnated using a vacuum-assisted resin injection process to ensure sufficient resin penetration into the woven fibers. Simultaneously, a plaster lost foam casting process is used, employing a plaster mandrel during sample preparation. After curing, the inner core is removed using the plaster lost foam casting method, ultimately producing the composite spring.

[0041] (4) The optimized spacer structure improves the reliability and performance of the braking system: The traditional triangular wave pleated rubber structure of the spacer is optimized into a continuous sine wave structure, and annular wedge-shaped sealing grooves are provided at both ends of the spacer body. At the same time, a braided layer is added to the middle layer of the rubber. This design can more evenly distribute stress, effectively reducing rubber fatigue and cracking caused by stress concentration, thereby extending the service life of the spacer. After the sealing groove is changed from trapezoidal to wedge-shaped, the sealing performance of the spacer is significantly improved, ensuring the sealing effect even under high pressure or frequent use. The addition of the braided layer enhances the structural strength and flexibility of the spacer, which not only improves its fatigue resistance, but also reduces the maintenance requirements and costs of the system, thereby enhancing the stability and safety of the entire vehicle braking system.

[0042] (5) Optimization of the Vehicle Braking System through Lightweighting and Performance Improvement of Composite Springs: Composite springs were fabricated using ring weaving technology and mold curing techniques. These helical springs combine carbon fiber and basalt fiber at a 45° angle, fully leveraging the mechanical advantages of both fibers. This design flexibly combines the strength and toughness of the fibers, significantly reducing the spring's weight and thus lowering the overall vehicle weight, improving energy efficiency and driving range. Composite springs possess stronger multi-directional load-bearing capacity and fatigue durability under complex stress environments, which is crucial for improving the overall reliability of the vehicle's braking system. Compared to traditional metal springs, the use of composite materials reduces the risk of fatigue failure, especially during frequent braking operations, ensuring long-term efficient spring operation and improving the vehicle's braking response speed and stability. Attached Figure Description

[0043] Figure 1 This is a cross-sectional view of the sandwich structure of "rubber-woven layer-rubber" in this application document;

[0044] Figure 2 This is a schematic diagram of the spacer structure in this application document;

[0045] Figure 3 This is a schematic diagram of the structure of carbon fiber and basalt fiber mixed on a polyurethane rod as described in this application document;

[0046] Figure 4 This is a schematic diagram of the effect of 45° circular weaving of carbon fiber and basalt fiber in this application document;

[0047] Figure 5 This is a schematic diagram illustrating the effect of carbon fiber and basalt fiber being interwoven on a polyurethane rod, as described in this application.

[0048] In the figure: 1. Outer rubber layer of spacer; 2. Inner rubber layer of spacer; 3. Braided layer; 4. Metal rod; 5. First wedge-shaped sealing groove; 6. Second wedge-shaped sealing groove; 7. Carbon fiber; 8. Basalt fiber; 9. Polyurethane rod; 10. Resin composite material of carbon fiber-basalt fiber hybrid. Detailed Implementation

[0049] 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.

[0050] like Figures 1-5 As shown, the technical solution adopted by the present invention is as follows: This embodiment provides a vacuum booster device for an automotive braking system, comprising:

[0051] A spacer sleeve is installed inside the vacuum booster device; the spacer sleeve includes a bent portion in the middle and mounting portions at both ends of the bent portion, the bent portion having a sinusoidal wave structure; and each mounting portion is provided with a wedge-shaped sealing structure.

[0052] A composite material spring is installed inside the vacuum booster device, and the composite material spring is woven using a ring-shaped weaving technique.

[0053] The spacer includes, from the outside to the inside, an outer layer of rubber 1, a braided layer 3, and an inner layer of rubber 2;

[0054] The wedge-shaped sealing structures at both ends of the spacer, located at their mounting portions, are respectively provided with a first wedge-shaped sealing groove 5 and a second wedge-shaped sealing groove 6.

[0055] The spacer in a vacuum booster is a critical sealing component located inside the booster. It prevents atmospheric air from entering the booster's vacuum section, ensuring the booster can properly amplify the braking force applied by the driver, thus improving braking efficiency and safety. Furthermore, the spacer's flexibility and durability play a vital role in frequent braking operations, ensuring the system's stability over extended periods.

[0056] In another embodiment, the traditional spacer is structurally innovated by adding a braided layer 3 between the inner and outer layers of the spacer, which improves the sealing characteristics of the vacuum assist device and enhances the durability of the spacer itself.

[0057] In another embodiment, the spacer includes a central cylindrical body with annular first wedge-shaped sealing groove 5 and second wedge-shaped sealing groove 6 at both ends of the body. The middle part of the spacer body is changed from a pleated triangular waveform to a continuous sine wave structure, and a braided layer 3 is added between the inner rubber layer 1 and the outer rubber layer 2 of the spacer. The sealing grooves at both ends of the spacer are changed from trapezoidal to wedge-shaped.

[0058] This embodiment also provides a method for manufacturing a vacuum booster device for an automotive braking system, wherein the spacer is manufactured using a hot-press vulcanization process combined with ring weaving technology to ensure the stability of the spacer's dimensions and performance. The manufacturing method steps are as follows:

[0059] Step 1: Install the required size metal rod 4 on the circular braiding machine and evenly spray LW-369 rubber release agent onto the surface of the metal rod 4 to ensure smooth demolding later.

[0060] Furthermore, the dimensions of the metal rod 4 are selected based on the inner and outer diameters and length of the spacer used in the vacuum booster device.

[0061] Step 2: Select natural compound rubber and cut it into sheets of appropriate size. Using a manual winding process, wrap the cut natural compound rubber around the metal rod 4 that has been coated with release agent. The ends of the rubber are pressed tightly together by manual compression and evenly covered on the metal rod 4 to form a complete cylindrical shape, namely the inner layer rubber 2 of the spacer.

[0062] Furthermore, when using a manual winding process, it is essential to ensure that appropriate tension is maintained during the winding process, that the surface of the rubber layer is flat and free of gaps, and that stability is maintained during the subsequent weaving process.

[0063] Step 3: Using a circular braiding machine, weave nylon fibers evenly onto the surface of the inner rubber layer 2 of the spacer at a 45° angle.

[0064] Furthermore, the fiber type, mixing ratio, and model can be flexibly adjusted according to the usage requirements. This invention does not limit these aspects, but it should ensure that the selected fibers have good adhesion to the rubber material to avoid interlayer separation.

[0065] Furthermore, after weaving is completed, the fiber weave layer should be tightly adhered to the surface of the inner rubber layer 2 of the spacer to form the weave layer 3 of the spacer for the vacuum assist device.

[0066] Step 4: After weaving is completed, continue to use the manual winding process to evenly wind the second layer of natural compound rubber onto the weaving layer 3, which is the outer layer rubber 1 of the spacer.

[0067] Furthermore, through steps one through four of the above-mentioned spacer preparation process, a sandwich structure of "rubber-woven layer-rubber" is ultimately formed, such as... Figure 1 As shown. Figure 1 The diagram shows a cross-sectional view of a "rubber-braided layer-rubber" sandwich structure, where the middle braided layer 3 is sandwiched between the inner rubber layer 2 and the outer rubber layer 1, with the metal rod 4 serving as the supporting substrate.

[0068] Furthermore, the thickness of the natural rubber compound is half the thickness of the spacer sleeve required for the vacuum booster device. The dimensions of the natural rubber compound are cut according to the diameter and length of the metal rod 4 to be wound.

[0069] Furthermore, the natural compounded rubber is a conventional formula containing common chemical components such as vulcanizing agents, accelerators, antioxidants, and plasticizers, which are uniformly dispersed in the rubber matrix. This invention does not make any special description of this.

[0070] Step 5: Demold the aforementioned "rubber-braided layer-rubber" sandwich structure from the metal rod 4 of the annular braiding machine, ensuring that the rubber structure and braided layer 3 are not damaged during the demolding process. Perform appropriate surface cleaning and trimming on the demolded sandwich structure. Wrap the tidied sandwich structure around the inner mold shaft of the corresponding spacer mold and place it on the lower mold of the spacer mold to close it with the corresponding upper mold.

[0071] Furthermore, the spacer mold is equipped with an annular wedge-shaped sealing groove adapted to the size of the spacer, as well as an inner cavity with a sinusoidal wave structure. The annular wedge-shaped sealing groove and sinusoidal wave structure in the spacer mold are matched with the design of the rubber spacer.

[0072] Furthermore, the spacer mold consists of three parts: upper and lower molds and an inner mold shaft. The upper and lower molds are located at the top and bottom of the mold, respectively, while the inner mold shaft is located between the upper and lower molds and is detachable. The inner mold shaft is fixed inside the upper and lower molds by a positioning structure to ensure precise alignment during the molding process. After molding, the detachable inner mold shaft facilitates demolding. The upper and lower molds are coordinated by a guiding device.

[0073] Furthermore, before placing the aforementioned "rubber-woven layer-rubber" sandwich structure into the spacer mold, to ensure that the rubber material can be smoothly separated from the spacer mold, a sufficient amount of LW-369 rubber release agent should be evenly sprayed onto the surfaces of the upper and lower molds and the inner mold shaft.

[0074] Step 6: Place the above-mentioned spacer mold in a flat vulcanizing machine, set the vulcanization time, temperature and pressure, and carry out the vulcanization treatment.

[0075] Furthermore, the vulcanization parameters (such as time, temperature, pressure, etc.) need to be adjusted according to the performance of the rubber material and the process requirements, and this invention does not impose specific limitations on them.

[0076] Step 7: After vulcanization is complete, gradually cool the spacer mold, remove the vulcanized spacer from the mold, remove excess material from the edges and corners, and perform surface finishing to obtain the final product.

[0077] Furthermore, the surface of the spacer can be treated with anti-corrosion or wear-resistant coatings according to actual needs to improve the service life and durability of the spacer.

[0078] The coil spring is a key elastic element within a vacuum booster, specifically located inside the booster. Different types of coil springs are distributed within the internal controller and chambers. The coil springs inside the controller primarily regulate the booster's opening and closing actions, while the coil springs in the chambers are responsible for resetting the piston, ensuring the system quickly returns to its initial state after braking. The coil springs endure repeated compression and release during frequent braking operations, requiring excellent fatigue durability. Furthermore, lightweight design of the coil springs is particularly important. In new energy vehicles and modern passenger cars, reducing spring weight lowers the overall vehicle weight, improving braking response speed and further enhancing overall braking performance and vehicle handling.

[0079] In another embodiment, a composite material spring is provided, which is formed by weaving carbon fiber and basalt fiber at a 45° angle using a ring-weaving technique. While maintaining high strength and toughness, it significantly reduces weight. The ring-weaving technique results in a more uniform fiber distribution in the composite spring, improving the multi-directional mechanical properties of the coil spring. This effectively disperses stress during braking, enhancing the spring's fatigue resistance and durability, and preventing fractures and deformations caused by metal fatigue. Compared to traditional metal coil springs, composite material springs offer the advantage of lightweight design, reducing overall vehicle weight and improving braking response speed and performance. Furthermore, the superior fatigue resistance of composite materials allows for rapid recovery from deformation during frequent braking operations, ensuring the normal operation of the vacuum booster device and preventing sluggish response due to fatigue or excessive weight. Especially under extreme driving conditions such as high-speed driving and emergency braking, the strength, toughness, and high stiffness of the composite material coil spring ensure that the system can respond promptly to the driver's braking requests, enhancing braking stability and handling, and meeting the requirements of modern passenger vehicles, especially new energy vehicles, for lightweight, high-performance braking systems.

[0080] In another embodiment, a composite material spring is prepared by carbon fiber-basalt fiber braiding, and the preparation process is described below:

[0081] Step 1: Select a suitable mandrel material as the support structure during the weaving process. Choose at least two or more fibers and weave them together using a circular braiding machine. This ensures high strength and lightweight properties while also offering cost optimization advantages. For example... Figure 3 As shown, this invention uses a ring weaving technique to interweave carbon fiber 7 and basalt fiber 8 at a 45° angle onto a polyurethane rod 9. By weaving layer by layer until the preset number of weaving layers and thickness are reached, the preform A is finally obtained.

[0082] Furthermore, the size and length of the polyurethane rod can be selected according to actual needs, and the fiber type, mixing ratio, and model can be flexibly adjusted according to usage requirements. This invention does not impose any limitations on these aspects.

[0083] Furthermore, during the layer-by-layer weaving process of the circular braiding machine, the diameter of the braided part will continuously increase after each layer is completed. It is necessary to dynamically adjust the extraction speed of the polyurethane rod by the braiding machine according to the current diameter of the braided part to ensure that the weaving angle is always kept within the preset angle range, thereby ensuring the mechanical properties and structural consistency of the final product.

[0084] Furthermore, such as Figure 4 The diagram shows a planar weaving pattern at ±45°. This invention utilizes 45° weaving to enhance the isotropic properties of the product, improving its shear resistance, fatigue resistance, and impact resistance, thus providing better load-bearing capacity under various loading conditions. Compared to using a single high-performance fiber (such as pure carbon fiber), blending different types of fibers based on ring weaving technology can reduce material costs while ensuring mechanical properties, making the product more competitive in the market.

[0085] Step 2: Based on the dimensional requirements of the designed composite material spring, preform A is trimmed and placed in a vacuum bag. A guide tube is connected to both ends of the vacuum bag, and the connection between the vacuum bag and the guide tube is sealed with sealant. One end of the guide tube is bent and sealed, while the other end is connected to a vacuum pump to remove air from the vacuum bag and maintain a continuous vacuum state to prevent air from entering and ensure the smooth progress of the subsequent resin injection process.

[0086] Step 3: After uniformly mixing epoxy resin AM-8960A and curing agent AM-8960B at a mass ratio of 100:26, place the mixture in a vacuum device to remove air bubbles, obtaining solution a. After confirming the vacuum bag is leak-free, insert the bent guide tube into solution a, and using the principle of vacuum negative pressure, continuously pump solution a to evenly penetrate all areas of preform A, ensuring complete wetting, ultimately forming preform B.

[0087] Furthermore, the time and negative pressure value throughout the impregnation process are controlled according to process requirements to ensure optimal resin penetration.

[0088] Step 4: Wrap the preform B around the mold cavity of the plaster mandrel, then fit it with the composite material spring metal mold, close the mold, and place it in an oven to heat and cure.

[0089] Furthermore, the plaster mandrel is made through a plaster mandrel metal mold. Both the plaster mandrel metal mold and the composite material spring metal mold are composed of three modules connected by bolts, which ensures the sealing of the composite material spring and plaster mandrel during the sample making process while applying a certain pressure to enable them to be formed.

[0090] In another embodiment, the molding and curing process of preform B is as follows:

[0091] S101. Plaster mandrels are made using a plaster mandrel metal mold.

[0092] S102. Wrap the precast part B around the mold cavity of the plaster mandrel;

[0093] S103. The plaster mandrel of the precast component B is closed by a composite material spring metal mold.

[0094] S104. Place the composite material spring metal mold from S103 into the oven, and adjust the oven to the appropriate temperature and time for heating and curing.

[0095] Furthermore, in the molding process of the composite material spring, firstly, a plaster mandrel is manufactured using a plaster mandrel metal mold. Secondly, the preform B is wound around the mold cavity of the plaster mandrel. Thirdly, the plaster mandrel with the preform B wound around it is placed on the corresponding composite material spring metal mold. Finally, the composite material spring metal mold provides overall external pressure and support to ensure that the preform B can be shaped within the specified shape range.

[0096] Furthermore, before winding the preform B around the plaster mandrel and before placing the plaster mandrel into the corresponding composite spring metal mold, an oil-based release agent VX710 is evenly sprayed onto the surface of the plaster mandrel and the surface of the composite spring metal mold. This ensures that a smooth isolation layer is formed between the preform B and the mold surface, preventing the preform from sticking to the mold during the curing process, facilitating subsequent demolding operations, and ensuring the smoothness and integrity of the composite spring surface.

[0097] Furthermore, the curing temperature and time are determined according to the curing requirements of epoxy resin AM-8960A and curing agent AM-8960B: 60℃ × 2 hours + 120℃ × 2 hours, and cooling is performed after ensuring the resin is fully cured. In addition, the curing temperature and time can be adjusted according to different resin systems; this invention does not impose limitations on these settings.

[0098] Step 5: After curing and molding, remove the plaster mandrel using the plaster disappearing plaster method, and then polish the demolded helical spring. The final composite material spring looks like... Figure 5 As shown, the outer layer is a resin composite material 10 made of carbon fiber-basalt fiber hybrid, which wraps the inner polyurethane rod 9.

[0099] Furthermore, the plaster removal method includes, but is not limited to, removing the plaster mandrel by crushing or pressurized water rinsing, ensuring that the surface of the helical spring sample is not damaged during the process. Depending on requirements, a coating treatment can be selectively applied to the product surface to further enhance its corrosion resistance and wear resistance.

[0100] In automotive braking systems, vacuum boosters play a crucial role in amplifying braking force, enabling drivers to obtain stronger braking force when pressing the brake pedal, thus achieving faster deceleration and braking response. However, with the increasing frequency of vehicle use and more complex operating conditions, traditional booster components such as metal coil springs and spacers have gradually revealed their shortcomings in terms of sealing, response speed, and fatigue durability. To address these issues, this invention optimizes two key components in the vacuum booster—the composite material coil spring and spacer—so that they not only improve their individual performance but also work synergistically during braking, significantly enhancing the overall efficiency and reliability of the system and jointly promoting efficient operation of the braking system under complex conditions.

[0101] Composite material helical springs are crucial elastic components in vacuum booster systems, directly impacting the braking system's response speed and stability. Especially during frequent braking operations, their design significantly enhances system stability and responsiveness. Located within the booster, the spring regulates its opening and closing through its elastic properties, ensuring the braking system reacts rapidly when the driver depresses the brake pedal. This invention utilizes a ring-weaving technique, blending carbon fiber and basalt fiber at a 45° angle, resulting in excellent strength, toughness, and fatigue durability. This design not only enhances the spring's load-bearing capacity but also effectively reduces the overall system weight, improving braking response speed. The high elasticity and fatigue resistance of the composite material spring allow it to withstand higher frequencies of compression and release, maintaining excellent elastic support throughout multiple operating cycles, thus significantly extending its service life. Under extreme braking conditions, the composite material spring quickly returns to its initial state, ensuring system stability and vehicle handling, guaranteeing the braking system's efficiency and safety.

[0102] The spacer plays a crucial role in sealing and isolation in vacuum booster devices. Traditional spacers suffer from insufficient sealing and rubber aging. This invention, however, improves the spacer's sealing performance and optimizes its load-bearing capacity by employing a sinusoidal wave structure, a wedge-shaped sealing groove design, and a rubber-woven layer-rubber structure. This reduces fatigue caused by stress concentration and ensures efficient and stable operation of the booster system. During braking, the spacer works in conjunction with the composite material helical spring. During the spring's compression and recovery, the spacer maintains the stability of the internal environment of the vacuum booster, ensuring a continuous and stable boost and preventing a weakening of braking force due to decreased sealing performance.

[0103] Throughout the braking process, the synergistic effect of the composite material helical spring and the optimized spacer ensures the efficient and stable operation of the vacuum booster, and further enhances the overall performance of the braking system in conjunction with the EPB (Electronic Parking Brake) system. The collaborative process mainly consists of the following parts:

[0104] 1. Initial Braking Response: When the driver depresses the brake pedal, the composite spring responds immediately, and its recovery speed and stability after brake release ensure precise operation of the braking system. The advantages of the composite spring accelerate the system's response, ensuring sensitive and accurate braking operation.

[0105] 2. Sealing Guarantee: As the helical spring is compressed, the optimized design of the spacer effectively maintains the stability of the internal environment of the power assist device, avoiding the reduction in braking effect caused by decreased sealing.

[0106] 3. Continuous operation and durability: With the synergistic effect of the composite material spring and the optimized spacer, the spring provides elastic support while the spacer maintains the sealing of the vacuum environment. The two complement each other to ensure the stability of the system in long-term use, reduce maintenance needs and costs, and extend service life.

[0107] 4. Emergency Braking and Assisted Braking: Under extreme braking conditions, the composite material coil spring can quickly return to its original position, providing sufficient braking force to ensure the vehicle can decelerate or stop in a timely manner. Simultaneously, the excellent sealing performance of the spacer prevents leakage from affecting braking force, ensuring the efficiency and reliability of braking operation under extreme conditions.

[0108] While EPB primarily relies on an electric motor to control the braking operation of the rear wheels, the vacuum booster and EPB work synergistically in certain critical scenarios. Specifically, in some vehicles, when the driver depresses the brake pedal, the vacuum booster amplifies the applied braking force and transmits it to the front and rear brakes, helping the vehicle decelerate quickly. If the system detects that more braking force is needed (such as in extreme emergency braking situations), the EPB will automatically activate, applying additional braking force to assist the vacuum booster in providing even greater braking power.

[0109] Furthermore, most passenger vehicles today are equipped with an Auto-Hold function, which uses the vacuum booster and EPB system to achieve braking and parking. Specifically, when the driver presses the brake pedal, the vacuum booster first completes the initial deceleration operation. After the vehicle comes to a complete stop, the EPB automatically activates and takes over the braking task, at which point the EPB releases the driver's need to use the foot brake. This linkage between the vacuum booster and the EPB system not only improves the vehicle's braking response speed and safety but also reduces the driver's workload, especially in new energy vehicles and high-end passenger vehicles, meeting the higher demands for lightweight, intelligent, and safe vehicles.

[0110] 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 vacuum booster for an automobile braking system, characterized in that: include: A spacer, the spacer is installed inside the vacuum booster; the spacer includes a bent portion located in the middle and mounting portions located at both ends of the bent portion, the bent portion is a sine wave structure; the mounting portions are provided with a wedge-shaped sealing structure; A composite material spring is installed inside the vacuum booster device, and the composite material spring is mixed and woven by ring weaving technology.

2. The vacuum booster device for automobile brake system according to claim 1, characterized in that: The spacer comprises a spacer outer layer rubber (1), a braided layer (3), and a spacer inner layer rubber (2) which are arranged in sequence from the outside to the inside; The wedge-shaped sealing structures at the mounting parts of the two ends of the spacer are respectively provided with a first wedge-shaped sealing groove (5) and a second wedge-shaped sealing groove (6).

3. A method for preparing a vacuum booster for an automobile brake system, comprising the vacuum booster for an automobile brake system according to claims 1 and 2, characterized in that: The preparation steps of the spacer include: Step 1: Select a metal rod (4) of suitable diameter according to the requirements and install it on the circular braiding machine; Step 2: Cut the natural compound rubber sheet into a suitable size according to the requirements, and evenly wind it onto the metal rod (4) in step 1 to form a complete round tube shape, i.e., the inner rubber layer of the spacer (2); Step 3: Using a circular braiding machine, the nylon fibers are evenly and tightly braided at an angle of 45 degrees on the inner rubber surface of the spacer sleeve in step 2 to form a braided layer (3); Step 4: Cut the natural compound rubber sheet into a suitable size according to the requirements, and evenly wind it onto the braided layer of step 3, i.e., the outer rubber layer of the spacer (1), to form a "rubber-braided layer-rubber" sandwich structure; Step 5, demoulding the sandwich structure in step 4 from the metal rod (4), trimming its surface, and performing compression molding and shaping through a spacer mold; Step 6: Place the spacer sleeve mold in step 5 in a flat vulcanizer, set the vulcanization time, temperature, and pressure, and perform vulcanization treatment; Step 7: Cool the spacer mold after vulcanization, take out the vulcanized spacer from the spacer mold, and trim the surface of the spacer to obtain the final product.

4. The method for preparing a vacuum booster for an automobile brake system according to claim 3, characterized in that: The thickness of the inner rubber layer (2) of the spacer and / or the thickness of the outer rubber layer (1) of the spacer is half the thickness of the spacer.

5. The method for preparing a vacuum booster for an automobile brake system according to claim 3, characterized in that: In step five, the spacer mold includes an inner mold shaft, an upper mold, and a lower mold; the upper mold and the lower mold are located at the top and bottom ends of the spacer mold respectively; the inner mold shaft is located between the upper mold and the lower mold, and is detachably arranged; the spacer mold is provided with an annular wedge-shaped sealing groove adapted to the size of the spacer, and an inner cavity with a sinusoidal wave structure.

6. The method for preparing a vacuum booster for an automobile brake system according to claim 5, characterized in that: In step five, the surface-trimmed sandwich structure is evenly and tightly wrapped on the inner mold shaft, then placed in the lower mold and closed by the upper mold.

7. The method for preparing a vacuum booster for an automobile brake system according to claim 3, characterized in that: The steps of preparing the composite material spring include: Step 1: Select a suitable mandrel as a supporting structure during the weaving process, select at least two fibers and mix them through a ring braiding machine; weave at least two fibers layer by layer until a preset number of braiding layers and thickness are reached to obtain a preform A; Step 2: Trim the preform A in step 1 and put it into a vacuum bag. Connect the two ends of the preform A to the guide tube and seal it, bend one end to seal it, and connect the other end to the vacuum pump to exhaust the air. Keep the vacuum bag in a vacuum state to ensure smooth resin injection. Step 3, mix the resin and the curing liquid in proportion and stir them thoroughly; put the stirred and mixed resin into a vacuum pump, extract the air in the resin, ensure that the resin is uniform and free of bubbles, and obtain solution a; insert the bent guide tube into solution a, and use the continuous suction action of the vacuum pump to evenly penetrate solution a into various areas of preform A to make it completely infiltrated, and finally form preform B; Step 4: Wrap the preform B into the mold cavity of the plaster core shaft, and then press-mold and solidify it through the composite material spring metal mold; Step 5: After solidification and molding, the plaster core shaft is removed by using the plaster disappearance method, and the composite material spring after demoulding is polished.

8. The method for preparing a vacuum booster for an automobile brake system according to claim 7, characterized in that: In step 4, the gypsum core shaft is made by a gypsum core shaft metal mold.

9. The method for preparing a vacuum booster for an automobile brake system according to claim 8, characterized in that: The process of compression molding and curing of preform B is as follows: S101, using a gypsum mandrel metal mold to produce a gypsum mandrel; S102, winding the prefabricated part B into the mold cavity of the gypsum core shaft; S103, closing the gypsum mandrel wrapped around the preform B through a composite material spring metal mold; S104, placing the composite material spring metal mold in S103 into an oven, and adjusting the oven to appropriate temperature and time for heating and curing.

10. The method for preparing a vacuum booster for an automobile brake system according to claim 7, characterized in that: In step 1, the two types of fibers include carbon fiber (7) and basalt fiber (8).

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