Disc brake friction plate riveting block impact force determination method and system

Abstract

The application discloses a kind of disc brake friction plate riveting block impact force determination method and system, the method includes the following steps: determine the position of friction plate riveting block relative to the axis, obtain the dynamics model of friction plate transmission system;Obtain the equivalent stiffness of rivet, and the meshing line relative displacement of rivet and friction plate;According to the equivalent stiffness of rivet obtained, the meshing line relative displacement of rivet and friction plate, determine riveting block impact force;According to the impact force obtained and the rivet quantity and position of single friction plate, determine riveting force.The application determines riveting block impact force according to the equivalent stiffness of rivet, the meshing line relative displacement of rivet and friction plate, simple and efficient, high precision, fast operation speed.

Description

Technical Field

[0001] This invention belongs to the field of disc brake technology, specifically relating to a method and system for determining the impact force of the riveting block of the disc brake friction pad. Background Technology

[0002] Disc brakes are hydraulically controlled, and their main components include the brake disc, brake caliper, brake pads, and brake lines. The brake disc is made of alloy steel and fixed to the wheel, rotating with it. Disc brakes are widely used in passenger cars; most cars now use them on all wheels, while a few use them only on the front wheels, in conjunction with drum brakes on the rear wheels, to provide the car with high directional stability during braking.

[0003] The friction blocks and core plates of disc brakes are generally connected by rivets. Since the inner hub of the brake often has problems such as torsional vibration and impact, if the parameters such as the position of the rivet hole and the process are not selected properly, plastic deformation is likely to occur, causing the connection between the friction block and the core plate to loosen, the braking effect to decrease or fail. Therefore, how to accurately determine the impact force of the friction pad rivet block is an urgent problem to be solved. Summary of the Invention

[0004] The present invention aims to solve the technical problems existing in the prior art. The purpose of the present invention is to provide a method and system for determining the impact force of the riveted block of the friction pad of a disc brake.

[0005] To achieve the above objectives, according to a first aspect of the present invention, a method for determining the impact force of a disc brake friction pad riveting block is disclosed, comprising the following steps:

[0006] By determining the position of the friction plate riveting block relative to the shaft center, the dynamic model of the friction plate transmission system is obtained;

[0007] Obtain the equivalent stiffness of the rivet, and the relative displacement of the meshing line between the rivet and the friction plate;

[0008] The impact force of the rivet block is determined based on the obtained equivalent stiffness of the rivet and the relative displacement of the meshing line between the rivet and the friction plate.

[0009] The force at the riveting joint is determined based on the obtained impact force and the number and location of the rivets on the single friction plate.

[0010] The method for determining the impact force of the rivet block of the disc brake friction plate of the present invention determines the impact force of the rivet block based on the equivalent stiffness of the rivet and the relative displacement of the meshing line between the rivet and the friction plate. The method is simple, efficient, accurate and fast.

[0011] According to a preferred embodiment of the present invention, the dynamic model of the friction plate transmission system is as follows:

[0012]

[0013] Let {θ1,θ2,θ3,θ4,x2,y2,x4,y4,x5,y5} be the degrees of freedom of the system, where θ1,θ2,...θ4 represent the torsional displacements of the first gear shaft, the inner hub spline, the second gear shaft, and the outer spline about the Z-axis; k t1 ,k t2 ,...,k t4 c t1 ,c t2 ,...,c t4 The values ​​represent the torsional stiffness and torsional damping of each component: the first gear shaft, the inner hub spline, the second gear shaft, and the outer spline. x1 represents the x-direction vibration displacement of the first gear shaft, and y1 represents the y-direction vibration displacement of the first gear shaft. x2 and y2 represent the x-direction and y-direction vibration displacements of the inner hub spline, respectively. x3 represents the x-direction vibration displacement of the second gear shaft, and y3 represents the y-direction vibration displacement of the second gear shaft. x4 and y4 represent the x-direction and y-direction vibration displacements of the outer spline, respectively. x5 and y5 represent the x-direction and y-direction vibration displacements of the friction plate, respectively. T d T L These are the engine drive torque and the load torque, respectively; F m For the total meshing force, F mx F my These are the components of the total meshing force along the X and Y directions, respectively; m1 and k p1 c p1 These represent the mass of the inner hub, the support stiffness, and the support damping, respectively; m2 is the mass of the core plate; m3 is the mass of the friction plate; r b Let i be the base circle radius of the spline. mn Let m be the transmission ratio between components m and n, g be the acceleration due to gravity, and F be the acceleration due to gravity. eq To withstand the impact of riveting, F x and F y G3 is the component of the riveting impact force in the X and Y directions; G3 is the weight of a single friction plate; F c For centrifugal force; F e To analyze the external forces acting on the object, i 23 This represents the transmission ratio.

[0014] By establishing a dynamic model of the friction plate transmission system, it is easy to obtain the relative displacement of the meshing line between the rivet and the friction plate.

[0015] According to yet another preferred embodiment of the present invention, the method for obtaining the equivalent stiffness k of the rivet is as follows:

[0016]

[0017] Where, k r For shear stiffness, k h For contact stiffness,

[0018]

[0019] Where E is the elastic modulus; t is the rivet length; R1 and R2 are the inner and outer radii of the rivet, respectively;

[0020] Contact stiffness k h Represented as:

[0021]

[0022] Where π is the mathematical constant pi; E is the elastic modulus; v is Poisson's ratio; and L is the rivet length.

[0023] The equivalent stiffness includes shear stiffness and contact stiffness, and the calculation method of this equivalent stiffness k provides the basis for calculating the effective impact force.

[0024] According to yet another preferred embodiment of the present invention, the relative displacement of the engagement lines of the rivet and the friction plate is:

[0025] Δm=(x5-x4)sinθ4-(y5-y4)cosθ4+r r θ4

[0026] r r This is the distance from the rivet to the center of the circle.

[0027] This method is simple to calculate and has a fast processing speed.

[0028] According to another preferred embodiment of the present invention, the impact force of the rivet block is:

[0029]

[0030] Where c i and c' i denoted by , where is the clearance between the rivet and the left and right sides of the rivet hole; c is the proportional damping; and k is the equivalent stiffness of the rivet.

[0031] This method can quickly and accurately calculate the impact force of the rivet block.

[0032] According to another preferred embodiment of the present invention, when a single friction plate has two rivets, the force is distributed according to its position relative to the center of mass, and the forces at rivet A and rivet B are respectively:

[0033]

[0034] Where L1 is the distance of rivet A from the centroid, and L2 is the distance of rivet B from the centroid.

[0035] To achieve the above objectives, according to a second aspect of the present invention, a disc brake friction pad riveting block impact force determination system is disclosed, comprising an information acquisition unit and a processing unit. The information acquisition unit acquires the position of the friction pad riveting block relative to the axis, as well as the number and position of rivets on a single friction pad. The information acquisition unit transmits the acquired information to the processing unit, and the processing unit obtains the riveting block impact force and the force at the riveting joint according to the disc brake friction pad riveting block impact force determination method of the present invention.

[0036] The disc brake friction pad riveting block impact force determination system of the present invention can quickly, efficiently and accurately determine the impact force of the riveting block based on the equivalent stiffness of the rivet and the relative displacement of the meshing line between the rivet and the friction pad.

[0037] 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

[0038] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0039] Figure 1 This is a flowchart of the algorithm for determining the impact force of the rivet block of the disc brake friction plate in a preferred embodiment of the present invention;

[0040] Figure 2 This is a dynamic model of the friction plate transmission system in a preferred embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of friction plate riveting in a preferred embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of the rivet impact force distribution in a preferred embodiment of the present invention. Detailed Implementation

[0043] Embodiments of the present invention 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 the present invention, and should not be construed as limiting the present invention.

[0044] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "vertical", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" 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 invention 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 invention.

[0045] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0046] This invention discloses a method for determining the impact force of the riveting block of the friction pad in a disc brake, such as... Figure 1 As shown, it includes the following steps:

[0047] By determining the position of the friction plate riveting block relative to the shaft center, the dynamic model of the friction plate transmission system is obtained;

[0048] Obtain the equivalent stiffness of the rivet, and the relative displacement of the meshing line between the rivet and the friction plate;

[0049] The impact force of the rivet block is determined based on the obtained equivalent stiffness of the rivet and the relative displacement of the meshing line between the rivet and the friction plate.

[0050] The force at the riveting joint is determined based on the obtained impact force and the number and location of the rivets on the single friction plate.

[0051] The method for determining the impact force of the rivet block of the disc brake friction plate of the present invention determines the impact force of the rivet block based on the equivalent stiffness of the rivet and the relative displacement of the meshing line between the rivet and the friction plate. The method is simple, efficient, accurate and fast.

[0052] In a preferred embodiment of the present invention, such as Figure 2 and Figure 3 As shown, the dynamic model of the friction plate transmission system is:

[0053]

[0054] Let {θ1,θ2,θ3,θ4,x2,y2,x4,y4,x5,y5} be the degrees of freedom of the system, where θ1,θ2,...θ4 represent the torsional displacements of the first gear shaft, the inner hub spline, the second gear shaft, and the outer spline about the Z-axis; k t1,k t2 ,...,k t4 c t1 ,c t2 ,...,c t4 The values ​​represent the torsional stiffness and torsional damping of each component: the first gear shaft, the inner hub spline, the second gear shaft, and the outer spline. x1 represents the x-direction vibration displacement of the first gear shaft, and y1 represents the y-direction vibration displacement of the first gear shaft. x2 and y2 represent the x-direction and y-direction vibration displacements of the inner hub spline, respectively. x3 represents the x-direction vibration displacement of the second gear shaft, and y3 represents the y-direction vibration displacement of the second gear shaft. x4 and y4 represent the x-direction and y-direction vibration displacements of the outer spline, respectively. x5 and y5 represent the x-direction and y-direction vibration displacements of the friction plate, respectively. T d T L These are the engine drive torque and the load torque, respectively; F m For the total meshing force, F mx F my These are the components of the total meshing force along the X and Y directions, respectively; m1 and k p1 c p1 These represent the mass of the inner hub, the support stiffness, and the support damping, respectively; m2 is the mass of the core plate; m3 is the mass of the friction plate; r b Let i be the base circle radius of the spline. mn Let m be the transmission ratio between components m and n, g be the acceleration due to gravity, and F be the acceleration due to gravity. eq To withstand the impact of riveting, F x and F y G3 is the component of the riveting impact force in the X and Y directions; G3 is the weight of a single friction plate; F c For centrifugal force; F e To analyze the external forces acting on the object, i 23 This represents the transmission ratio.

[0055] By establishing a dynamic model of the friction plate transmission system, it is easy to obtain the relative displacement of the meshing line between the rivet and the friction plate.

[0056] In a preferred embodiment of the present invention, the method for obtaining the equivalent stiffness k of the rivet is as follows:

[0057]

[0058] Where, k r For shear stiffness, k h For contact stiffness,

[0059]

[0060] Where E is the elastic modulus; t is the rivet length; R1 and R2 are the inner and outer radii of the rivet, respectively;

[0061] Contact stiffness k h Represented as:

[0062]

[0063] Where π is the mathematical constant pi; E is the elastic modulus; v is Poisson's ratio; and L is the rivet length.

[0064] The equivalent stiffness includes shear stiffness and contact stiffness, and the calculation method of this equivalent stiffness k provides the basis for calculating the effective impact force.

[0065] According to yet another preferred embodiment of the present invention, the relative displacement of the engagement lines of the rivet and the friction plate is:

[0066] Δm=(x5-x4)sinθ4-(y5-y4)cosθ4+r r θ4

[0067] r r This is the distance from the rivet to the center of the circle.

[0068] This method is simple to calculate and has a fast processing speed.

[0069] In a preferred embodiment of the present invention, the impact force of the riveting block is:

[0070]

[0071] Where c i and c' i denoted by , where is the clearance between the rivet and the left and right sides of the rivet hole; c is the proportional damping; and k is the equivalent stiffness of the rivet.

[0072] This method can quickly and accurately calculate the impact force of the rivet block.

[0073] According to yet another preferred embodiment of the present invention, such as Figure 4 As shown, when a single friction plate has two rivets, the force is distributed according to its position relative to the center of mass. The forces at rivet A and rivet B are respectively:

[0074]

[0075] Where L1 is the distance of rivet A from the centroid, and L2 is the distance of rivet B from the centroid.

[0076] In this invention, the forces at riveting points A and B are obtained respectively. The twisting of the friction plate is the critical condition. By judging whether the friction plate twists, the stress limit values ​​at riveting points A and B are obtained. When the forces at riveting points A and B reach the stress limit values ​​during operation, an early warning is issued.

[0077] To achieve the above objectives, according to a second aspect of the present invention, a disc brake friction pad riveting block impact force determination system is disclosed, comprising an information acquisition unit and a processing unit. The information acquisition unit acquires the position of the friction pad riveting block relative to the axis, as well as the number and position of rivets on a single friction pad. The information acquisition unit transmits the acquired information to the processing unit, and the processing unit obtains the riveting block impact force and the force at the riveting joint according to the disc brake friction pad riveting block impact force determination method of the present invention.

[0078] The disc brake friction pad riveting block impact force determination system of the present invention can quickly, efficiently and accurately determine the impact force of the riveting block based on the equivalent stiffness of the rivet and the relative displacement of the meshing line between the rivet and the friction pad.

[0079] In the description of this specification, references to terms such as "preferred embodiment," "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0080] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for determining the impact force of the riveted block of a disc brake friction pad, characterized in that, Includes the following steps: By determining the position of the friction plate riveting block relative to the shaft center, the dynamic model of the friction plate transmission system is obtained; Obtain the equivalent stiffness of the rivet, and the relative displacement of the meshing line between the rivet and the friction plate; The impact force of the rivet block is determined based on the obtained equivalent stiffness of the rivet and the relative displacement of the meshing line between the rivet and the friction plate. The force at the riveting joint is determined based on the obtained impact force and the number and location of the rivets on the single friction plate. The dynamic model of the friction plate transmission system is as follows: ， by As the degrees of freedom of the system, among them... The first gear shaft, inner hub spline, second gear shaft, and outer spline components undergo torsional displacement around the Z-axis; , These are the torsional stiffness and torsional damping of each component; Let x be the vibration displacement of the first gear shaft in the x-direction. The vibration displacement of the first gear shaft in the y-direction; These represent the vibration displacement in the x-direction and the vibration displacement in the y-direction of the inner hub spline, respectively. The x-direction vibration displacement of the second gear shaft is given. This represents the vibration displacement of the second gear shaft in the y-direction. These represent the vibration displacements in the x and y directions of the external spline, respectively. These represent the vibration displacements of the friction plate in the x and y directions, respectively; T d T L These are the engine drive torque and the load torque, respectively; F m For the total meshing force, F mx F my These are the components of the total meshing force along the X and Y directions, respectively; m1 and k p1 c p1 These represent the mass of the inner hub, the support stiffness, and the support damping, respectively; m2 is the mass of the core plate; m3 is the mass of the friction plate; r b Let i be the base circle radius of the spline. mn Let m be the transmission ratio between components m and n, g be the acceleration due to gravity, and F be the acceleration due to gravity. eq To withstand the impact of riveting, F x and F y G3 is the component of the riveting impact force in the X and Y directions; G3 is the weight of a single friction plate; F c For centrifugal force; F e To analyze the external forces acting on the object, Represents the transmission ratio; The relative displacement of the meshing lines of the rivet and the friction plate is: ， This is the distance from the rivet to the center of the circle.

2. The method for determining the impact force of the riveted block of the disc brake friction pad according to claim 1, characterized in that, Obtain the equivalent stiffness of the rivet. The method is as follows: ， Where, k r For shear stiffness, k h For contact stiffness, ， Where E is the elastic modulus; t is the rivet length; R1 and R2 are the inner and outer radii of the rivet, respectively; Contact stiffness Represented as: ， in, π is pi; E is the modulus of elasticity; v is Poisson's ratio; L is the rivet length.

3. The method for determining the impact force of the riveted block of the disc brake friction pad according to claim 1, characterized in that, The impact force of the rivet block is: ， Among them, c i and c ’ i ρ represents the clearance between the rivet and the left and right sides of the rivet hole; c represents the proportional damping. This is the equivalent stiffness of the rivet.

4. The method for determining the impact force of the riveted block of the disc brake friction pad according to claim 1, characterized in that, When a single friction plate has two rivets, the force is distributed according to its position relative to the center of mass. The forces at rivet A and rivet B are as follows: ， in, Let A be the distance from the centroid of rivet A. This is the distance of rivet B from the centroid.

5. A system for determining the impact force of a disc brake friction pad riveting block, characterized in that, The system includes an information acquisition unit and a processing unit. The information acquisition unit acquires the position of the friction plate riveting block relative to the axis, as well as the number and position of rivets on a single friction plate. The information acquisition unit transmits the acquired information to the processing unit. The processing unit obtains the impact force of the riveting block and the force at the riveting joint according to the method described in any one of claims 1-4.

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