A light-weight method for brake components of a new energy vehicle based on regenerative braking theory and a new energy vehicle

Abstract

The application discloses a light-weight method of a new energy vehicle brake component based on a regenerative braking theory and a new energy vehicle, and the method comprises the following steps: determining vehicle parameters and a road adhesion coefficient; performing mechanical simulation analysis on the entire friction braking system; calculating the maximum ground braking force borne by a single wheel of a front axle; determining the braking force at the single wheel under the highest vehicle speed condition; calculating the maximum friction braking force of the single wheel of the front axle and the normal pressure borne by a single side of a brake disc; performing size optimization on a brake caliper according to the reduction of the maximum friction braking force and the reduction of brake pad thickness; and performing strength and rigidity analysis on the friction braking system. The regenerative braking theory is considered in the light-weight design of the brake caliper of the friction braking system, the brake caliper of the friction braking system is subjected to size optimization, and the overall performance and requirements of the brake caliper after light-weighting do not decrease compared with the brake caliper of the friction braking system before light-weighting, and the brake caliper has the same strength and rigidity as before.

Description

Technical Field

[0001] This invention relates to the field of braking technology for new energy vehicles, and in particular to a method for lightweighting brake components for new energy vehicles based on regenerative braking theory, and a new energy vehicle. Background Technology

[0002] As a replacement for traditional gasoline-powered vehicles, new energy vehicles offer advantages such as lower emissions, higher energy efficiency, and longer driving range. However, due to the significant weight of the battery systems in new energy vehicles, reducing the overall vehicle weight has become a major technical challenge in order to improve energy efficiency and driving range.

[0003] Brake calipers in automotive friction braking systems are typically made of materials such as cast iron or aluminum alloy, resulting in significant weight that increases the overall load on the vehicle and negatively impacts powertrain economy and suspension responsiveness. In the context of automotive lightweighting, reducing the weight of brake calipers has become a crucial approach to lowering overall vehicle weight and improving powertrain economy and handling performance.

[0004] Existing methods for reducing brake caliper weight primarily focus on using new materials or optimizing their structural design. For example, patent application CN113614407A discloses a brake designed for weight reduction by creating a thinning section on the inner surface of the caliper's bridge portion that gradually thins towards the center of the disc axis. This thinning section is formed by two gradually thinning inclined surfaces. This method can lead to stress concentration at the intersection of the two thinning inclined surfaces, resulting in a decrease in mechanical performance.

[0005] The lightweight structure of a disc brake caliper disclosed in patent number CN216715052U features six weight-reduction grooves at different locations. While this method significantly reduces weight, it only considers ensuring structural strength without verifying the stiffness of the braking system after weight reduction, potentially leading to non-compliance with stiffness design requirements.

[0006] In addition, patent number CN218913536U discloses a topology optimization structure for automotive calipers. This structure features multiple heat dissipation holes at the center of the caliper body and an oil inlet on one side. The caliper also includes oil channels, resulting in a lightweight structure. Both the caliper body and the oil channels are 3D-printed high-temperature alloy parts. While this method achieves both weight reduction and improved heat dissipation, the high cost of 3D printing technology prevents mass production.

[0007] The aforementioned lightweight brake caliper methods do not consider the impact of regenerative braking in new energy vehicles. New energy vehicles can brake using regenerative braking at low speeds and employ a hybrid braking mode combining regenerative and frictional braking at high speeds. In practice, the electric motor provides some braking force during braking in new energy vehicles. Therefore, the maximum braking force provided by brakes designed for traditional fuel vehicles exceeds the actual braking force required. This means that the frictional force provided by existing new energy vehicle brakes is excessive, directly leading to an oversized and heavy braking system, increasing manufacturing costs and overall vehicle weight, as well as increased drag and energy consumption. Therefore, lightweight design of the friction braking system for new energy vehicles is crucial. However, due to the addition of regenerative braking, there is still room for weight reduction in existing brake calipers. Summary of the Invention

[0008] The purpose of this invention is to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a lightweighting method for brake components of new energy vehicles based on regenerative braking theory, which reduces the structural weight of the brake caliper in the friction braking system while ensuring that the strength and rigidity of the brake caliper remain equivalent to the original.

[0009] This invention also proposes a new energy vehicle using the aforementioned lightweighting method for brake components of new energy vehicles based on regenerative braking theory.

[0010] A method for lightweighting brake components of new energy vehicles based on regenerative braking theory according to a first aspect of the present invention includes the following steps:

[0011] S1: Determine the vehicle parameters and road adhesion coefficient φ of the new energy vehicle;

[0012] S2: Before lightweighting the brake calipers, a mechanical simulation analysis of the entire friction braking system is performed, focusing on the strength of the brake calipers and the stiffness of the entire friction braking system.

[0013] Calculate the maximum ground braking force F exerted on a single wheel of the front axle;

[0014] The calculation of the regenerative braking force of the motor under the maximum vehicle speed condition is determined, and then the braking force F at a single wheel is calculated. reg ;

[0015] S3: Calculate the maximum frictional braking force of a single wheel on the front axle:

[0016] F f =FF reg ;

[0017] S4: Calculate the normal force on one side of the brake disc:

[0018]

[0019] Where μ is the coefficient of friction between the brake pads and the brake disc;

[0020] S5: Optimize the caliper size based on the reduction in maximum friction braking force and brake pad thickness;

[0021] S6: After weight reduction, perform strength and stiffness analysis on the friction braking system. If the strength of the brake caliper and the stiffness of the friction braking system are greater after weight reduction than before weight reduction, then size optimization is required. If they are less than or equal to the initial strength and stiffness, then the requirements are met.

[0022] The lightweighting method for brake components of new energy vehicles based on regenerative braking theory according to the first aspect of the present invention has at least the following beneficial effects: by incorporating regenerative braking theory into the lightweight design of brake calipers for friction braking systems, since existing regenerative braking technology can already meet braking under normal conditions, the size optimization of brake calipers for friction braking systems ensures that the overall performance and requirements of the lightweight brake calipers are not reduced compared to the brake calipers of the friction braking systems before lightweighting, and they still have comparable strength and rigidity as before.

[0023] According to the first aspect of the present invention, the method for lightweighting brake components of new energy vehicles based on regenerative braking theory includes dimensional optimization of the caliper, comprising:

[0024] The stress at the circumference of the piston bore before weight reduction is:

[0025]

[0026] Where D is the outer diameter of the cylinder before weight reduction, and d is the inner diameter of the cylinder before weight reduction;

[0027] Among these measures, reducing the positive pressure decreases the outer diameter D of the hydraulic cylinder to maintain stress. constant.

[0028] According to the first aspect of the present invention, the method for lightweighting brake components of new energy vehicles based on regenerative braking theory further includes dimensional optimization of the caliper, which includes:

[0029] The stress at the bottom of the piston bore before weight reduction is:

[0030]

[0031] Where A2 is the area of ​​the piston bore, and t1 is the thickness of the bottom of the cylinder before weight reduction;

[0032] Among these measures, reducing the bottom thickness after decreasing the normal pressure helps maintain stress. constant.

[0033] According to the first aspect of the present invention, the method for lightweighting brake components of new energy vehicles based on regenerative braking theory further includes dimensional optimization of the caliper, which includes:

[0034] Reduce the thickness t2 on the outer side of the clamp bridge and the thickness t3 on the outer side of the clamp reaction part;

[0035] According to the first aspect of the present invention, the method for lightweighting brake components of new energy vehicles based on regenerative braking theory further includes dimensional optimization of the caliper, which includes:

[0036] Based on the reduction in brake pad thickness, reduce the length L of the caliper bridge section;

[0037] According to the first aspect of the present invention, the lightweighting method for brake components of new energy vehicles based on regenerative braking theory ensures that the lightweighted caliper reaction part and caliper bridge part maintain the same strength as before.

[0038] According to a second aspect of the present invention, a new energy vehicle includes: a lightweighting method for new energy vehicle brake components based on regenerative braking theory as described in a first aspect of the present invention.

[0039] It is easy to understand that the new energy vehicle described in the second aspect of the present invention has the technical effects of the lightweight method for new energy vehicle brake components based on regenerative braking theory as described in the first aspect of the present invention, and therefore will not be repeated.

[0040] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0042] Figure 1 This is a flowchart of an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of an embodiment of the present invention. Detailed Implementation

[0044] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0045] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0046] In the description of this application, "several" means one or more, "more than" means at least two, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is for the purpose of distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0047] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly. Those skilled in the art can reasonably determine the specific meaning of the above terms in this application after considering the specific content of the technical solution.

[0048] Reference Figures 1 to 2 The first aspect of this application describes a lightweighting method for brake components of new energy vehicles based on regenerative braking theory. Starting from the regenerative braking theory of new energy vehicles, the method takes the maximum ground braking force and the regenerative braking force at the highest vehicle speed and the reduction of brake pad thickness as design standards, and the strength and stiffness of the brake caliper as constraints. Under the premise of ensuring that the strength and stiffness of the brake caliper are equivalent to the original, the method achieves structural lightweighting of the brake caliper of the friction braking system.

[0049] Based on this, the lightweighting method for brake components of new energy vehicles based on regenerative braking theory according to the first aspect of this application includes the following steps:

[0050] S1: Determine the vehicle parameters and road adhesion coefficient φ of the new energy vehicle;

[0051] S2: Before lightweighting the brake calipers, a mechanical simulation analysis of the entire friction braking system is performed, focusing on the strength of the brake calipers and the stiffness of the entire friction braking system.

[0052] Calculate the maximum ground braking force F exerted on a single wheel of the front axle;

[0053] The calculation of the regenerative braking force of the motor under the maximum vehicle speed condition is determined, and then the braking force F at a single wheel is calculated. rcgIt is understandable that during braking, the characteristic curve of a generator approximates that of a motor. Therefore, the maximum torque of the motor is constant at low and medium speeds, but decreases at high speeds because the motor outputs constant power at these speeds. To ensure safety, we take the vehicle's maximum speed as the reference point, calculate the regenerative braking force of the motor at this speed, and then calculate the braking force F applied to a single wheel. reg .

[0054] S3: Calculate the maximum frictional braking force of a single wheel on the front axle:

[0055] F f =FF reg ;

[0056] S4: Calculate the normal force on one side of the brake disc:

[0057]

[0058] Where μ is the coefficient of friction between the brake pads and the brake disc;

[0059] S5: Based on the reduction in maximum frictional braking force and brake pad thickness, the caliper dimensions are optimized; refer to Figure 2 Specifically, this includes the following:

[0060] (1) The stress at the bottom of the piston bore before weight reduction is:

[0061]

[0062] Where A2 is the area of ​​the piston bore, and t1 is the thickness of the bottom of the cylinder before weight reduction;

[0063] Among these measures, reducing the bottom thickness after decreasing the normal pressure helps maintain stress. constant;

[0064] (2) The stress at the circumference of the piston bore before weight reduction is:

[0065]

[0066] Where D is the outer diameter of the cylinder before weight reduction, and d is the inner diameter of the cylinder before weight reduction;

[0067] Among these measures, reducing the positive pressure decreases the outer diameter D of the hydraulic cylinder to maintain stress. constant;

[0068] (3) Reduce the thickness of the outer side of the clamp bridge and the outer side of the clamp reaction part;

[0069] (4) Reduce the length of the caliper bridge section according to the reduction in brake pad thickness;

[0070] (5) The reaction part and bridge part of the clamp body after the weight reduction should also maintain the same strength as before;

[0071] S6: After weight reduction, perform strength and stiffness analysis on the friction braking system. If the strength of the brake caliper and the stiffness of the friction braking system are greater after weight reduction than before weight reduction, then size optimization is required. If they are less than or equal to the initial strength and stiffness, then the requirements are met.

[0072] Reference Figures 1 to 2 The first aspect of this application describes a lightweighting method for brake components of new energy vehicles based on regenerative braking theory. This method incorporates regenerative braking theory into the lightweight design of brake calipers in friction braking systems. It considers the regenerative braking force provided by the electric motor during braking at maximum vehicle speed, while maintaining the total maximum ground braking force, thus reducing the friction braking force. Simultaneously, since existing regenerative braking technology can already meet braking requirements under normal conditions, the frequency of brake pad use is reduced, allowing for a reduction in pad thickness. Based on the reduction in friction braking force and the reduction in friction pad thickness, the dimensions of the brake caliper in the friction braking system are optimized. This ensures that the overall performance and requirements of the lightweight brake caliper are not reduced compared to the original friction braking system caliper, maintaining comparable strength and rigidity.

[0073] Reference Figures 1 to 2 The second aspect of this application describes a new energy vehicle, including a lightweighting method for brake components based on regenerative braking theory, as described in the first aspect of this application. The weight reduction of the brake caliper primarily considers the use of new materials and optimized structural design. The advantage of this method lies in linking the design principles of the brake caliper with the regenerative braking of the motor. By reducing the friction braking force and the thickness of the friction pads, the size of the brake caliper is reduced, while the strength and stiffness after lightweighting still meet the original design principles. Furthermore, the lightweighting principle proposed in this method can also be applied to the weight reduction of other components in the friction braking system, significantly improving the overall lightweighting effect of the friction braking system. The proposed method is not limited to the lightweighting of friction braking systems in front-axle driven new energy vehicles; it can also be applied to the lightweighting of friction braking systems in rear-axle driven and four-wheel drive new energy vehicles, thus enabling new energy vehicles using this method to achieve corresponding benefits.

[0074] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A method for lightweighting brake components of new energy vehicles based on regenerative braking theory, characterized in that, Includes the following steps: S1: Determine the vehicle parameters and road adhesion coefficient of the new energy vehicle. ; S2: Before lightweighting the brake calipers, a mechanical simulation analysis of the entire friction braking system is performed, focusing on the strength of the brake calipers and the stiffness of the entire friction braking system. Calculate the maximum ground braking force on a single wheel of the front axle ; The calculation of the regenerative braking force of the motor under the maximum vehicle speed condition is determined, and then converted to the braking force at a single wheel. ; S3: Calculate the maximum frictional braking force of a single wheel on the front axle: ； S4: Calculate the normal force on one side of the brake disc: ； in The coefficient of friction between the brake pads and the brake disc; S5: Optimize the caliper size based on the reduction in maximum friction braking force and brake pad thickness; S6: After weight reduction, perform strength and stiffness analysis on the friction braking system. If the strength of the brake caliper and the stiffness of the friction braking system after weight reduction are greater than those before weight reduction, then size optimization is required again. If they are less than or equal to the initial strength and stiffness, then the requirements are met. The caliper size optimization includes: The stress at the circumference of the piston bore before weight reduction is: ； in, The outer diameter of the hydraulic cylinder before weight reduction. The inner diameter of the hydraulic cylinder before weight reduction; Among them, the outer diameter of the oil cylinder is reduced after the positive pressure decreases. Thus maintaining stress constant; Dimensional optimization of calipers also includes: The stress at the bottom of the piston bore before weight reduction is: ； in, Let be the area of ​​the piston bore. The thickness of the bottom of the hydraulic cylinder before weight reduction; Among these measures, reducing the bottom thickness after decreasing the normal pressure helps maintain stress. constant.

2. The lightweighting method for brake components of new energy vehicles based on regenerative braking theory according to claim 1, characterized in that: Dimensional optimization of calipers also includes: Reduce the thickness of the outer side of the clamp body bridge. Thickness of the outer side of the reaction part of the clamp body .

3. The lightweighting method for brake components of new energy vehicles based on regenerative braking theory according to claim 2, characterized in that: Dimensional optimization of calipers also includes: Reduce the length of the caliper bridge section based on the reduction in brake pad thickness. .

4. The lightweighting method for brake components of new energy vehicles based on regenerative braking theory according to claim 3, characterized in that: The lightweight clamp reaction part and clamp bridge part must still maintain the same strength as before.

5. A new energy vehicle, characterized in that, include: The lightweighting method for brake components of new energy vehicles based on regenerative braking theory as described in any one of claims 1 to 4.

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