A disc brake with active separation of magnetic and non-magnetic particles mechanism

Abstract

The application relates to a disc brake with a mechanism for actively separating magnetic and non-magnetic particles and a separation control method, belonging to the technical field of vehicles. The disc brake comprises a brake disc, a brake caliper, a steering knuckle and the mechanism for actively separating magnetic and non-magnetic particles. The mechanism for actively separating magnetic and non-magnetic particles comprises a shell, a pair of brake disc cleaning mechanisms, a magnetic particle cleaning mechanism and a fan mechanism. A pair of upper-layer air ducts, a lower-layer air duct and a cleaning channel are respectively arranged in the length direction of the shell; the pair of brake disc cleaning mechanisms are arranged on the inner walls of the two sides of the shell; the magnetic particle cleaning mechanism is arranged in the cleaning channel; a collecting cavity is arranged in the middle of the lower-layer air duct; a fan of the fan mechanism is arranged in the collecting cavity; and an electromagnetic coil is arranged on the bottom surface of the collecting cavity. The magnetic particles generated by the braking of the vehicle can be effectively collected in the collecting cavity, and the magnetic particles with a particle size of less than 80 microns can be effectively collected; and the non-magnetic particles are discharged through the cleaning channel below the closed end of the shell.

Description

Technical Field

[0001] This invention belongs to the field of vehicle technology, and specifically relates to a disc brake with an active mechanism for separating magnetic and non-magnetic particles. Background Technology

[0002] Brake discs are an indispensable component of vehicles, and vehicle braking largely depends on them. With the increasing popularity of electric vehicles, particulate pollution from brake disc braking is becoming increasingly prominent. The China Internal Combustion Engine Association included brake emission testing in its 2024 group standard plan, as particles generated during braking enter the atmosphere and pollute the surrounding environment. Because disc brakes have an open structure, external particles inevitably enter the surface of the brake pads, resulting in a large number of fine particles between the brake pads, as well as particles generated during disc braking, forming what is known as a "third body." The main sources of these particles are wear on the brake pads themselves and environmental particles entering the brake pads. Particles generated by wear on the brake pads primarily originate from the brake disc and brake pads. Currently, most vehicles use a combination of front ventilated discs and rear disc brakes; therefore, this patent selects a ventilated disc as the model for research.

[0003] Currently, brake discs mainly use gray cast iron 250 (HT250), alloy cast iron, and cermet. After asbestos-based brake blocks were phased out, brake blocks are mainly divided into three types: metal-based friction materials with metal powder as the matrix and appropriate amounts of lubricating and friction components added; semi-metallic friction materials, evolving from initial steel fibers to composite metal fibers; and non-metallic friction materials, including C / C and ceramic composite friction materials. For metal-based friction materials, the friction materials are mainly iron-based and copper-based, with a metal content exceeding 70%. For semi-metallic friction materials, iron, copper, and their alloy fibers and powders account for 40%-70%. According to particle size analysis experiments, generally speaking, the particle size generated by wear is mostly no more than 100μm, while the particle size of environmental particles is no more than 200μm, and the number of wear particles is also greater than that of environmental particles. Metal particulate pollutants are non-degradable; if released into the atmosphere, they can enter the human body through respiration, causing functional disorders and even various diseases.

[0004] Existing particle collection devices mainly include the following types: one type uses the wind pressure from a moving vehicle or an active fan to adsorb and collect particles from disc brakes. This type of device has high energy requirements and relies solely on wind pressure for particle adsorption, which cannot guarantee collection efficiency. Some particles cannot enter the collection mechanism and enter the atmosphere, resulting in poor collection performance. Another type uses a cyclone collector installed on the brake disc for collection. This device relies on high vehicle speeds to collect particles using the Venturi effect, and is greatly affected by vehicle speed. It cannot effectively collect particles at low vehicle speeds or when the vehicle is stopped. A third type uses a method of encasing the brake pads to collect particles. This device is bulky, and the brake pads cannot obtain the necessary cooling source, leading to reduced braking performance or even failure. Zhao Xin's paper on a device for collecting brake dust from vehicle disc brakes describes a method where particles on the brake discs are separated by a stripping mechanism and collected in a cyclone collector. However, the collection effect is not evaluated, and magnetic and non-magnetic particles are not separated. Furthermore, most current particle recovery research collects all particles into a single collection mechanism without separating magnetic from non-magnetic particles. This leads to difficulties in handling the remaining non-magnetic particles during post-collection recovery. Current research largely focuses on structural innovation, failing to adequately evaluate the mechanism's recovery capabilities. The particle size generated by brake disc friction is not fully identifiable, and the inability to assess the mechanism's recovery efficiency means that it's impossible to anticipate the inability to recover certain particles generated during operation. Current research evaluating recovery efficiency primarily focuses on cyclone collectors. While cyclone collectors of different structures and sizes exhibit good collection efficiency for particles larger than 20 micrometers in diameter, their efficiency is low for particles smaller than 20 micrometers, and the smaller the particle diameter, the lower the collection efficiency. Summary of the Invention

[0005] In order to effectively separate and collect particles on the brake disc under vehicle braking conditions, based on the vehicle's speed, this invention provides a disc brake with an active mechanism for separating magnetic and non-magnetic particles.

[0006] A disc brake with an active mechanism for separating magnetic and non-magnetic particles includes a brake disc 2, a brake caliper 1, and a steering knuckle 3. It also includes the active mechanism for separating magnetic and non-magnetic particles.

[0007] The active separation mechanism for magnetic and non-magnetic particles includes a housing 6, a pair of brake disc cleaning mechanisms, a magnetic particle cleaning mechanism, and a fan mechanism;

[0008] The shell 6 is a long, flat box with an open top;

[0009] The lower part of the brake disc 2 is located inside the housing 6;

[0010] One end of the shell 6 along its length is a closed end, and the other end is an open end;

[0011] Upper ventilation channels 7 are respectively provided on the two side walls of the open end of the shell 6, and the upper ventilation channels 7 are parallel to the bottom surface of the shell 6;

[0012] The inner side of the other end of the shell 6 along the length direction is an inclined surface 22 that slopes towards the open end; a cleaning channel 12 is provided in the length direction of the shell 6 below the inclined surface 22, the cleaning channel 12 is parallel to the bottom surface of the shell 6 and passes through the closed end of the shell 6.

[0013] The bottom of the housing 6 is provided with a lower ventilation duct 8 along its length, and the lower ventilation duct 8 is located parallel to the bottom of the cleaning channel 12.

[0014] The inner sides of the housing 6 are respectively provided with recessed mounting grooves, and a pair of brake disc cleaning mechanisms are symmetrically arranged in the mounting grooves;

[0015] The brake disc cleaning mechanism includes a first cleaning rod 9, a first driving rod 14, and a first motor 27 connected in sequence. The first cleaning rod 9 is a T-shaped rod, wherein the horizontal rod is a cleaning rod and the vertical rod is a driven rod. The outer end of the driven rod is hinged and disposed in the mounting groove. The working end of the first driving rod 14 is in movable contact with the middle of the driven rod, and the other end of the first driving rod 14 is fixedly connected to the output shaft of the first motor 27. When the first motor 27 is working, the cleaning rod of the first cleaning rod 9 is driven to reciprocate by the swing of the first driving rod 14.

[0016] The cleaning rods of the pair of first cleaning rods 9 of the pair of brake disc cleaning mechanisms contact the two sides of the brake disc respectively;

[0017] The magnetic particle cleaning mechanism includes a second cleaning rod 17, an intermediate connecting rod 16, a second driving rod 15, and a second motor 10 connected in sequence; wherein the second cleaning rod 17, the intermediate connecting rod 16, and the second driving rod 15 constitute a planar linkage mechanism, the planar linkage mechanism is located on the bottom surface inside the cleaning channel 12, and the second motor 10 is fixedly installed at the top inside the cleaning channel 12.

[0018] A magnetic particle collection chamber 20 is provided in the lower ventilation duct 8 below the middle of the cleaning channel 12, and an electromagnetic coil 21 is provided on the bottom surface of the magnetic particle collection chamber 20.

[0019] The fan mechanism includes a fan 19 and a fan motor 24; the fan 19 is located in the magnetic particle collection chamber 20 of the lower ventilation duct 8, and the fan motor 24 is fixedly installed at the top of the cleaning channel 12.

[0020] The further defined technical solution is as follows:

[0021] The inlet of the upper ventilation duct 7 is located at the open end of the shell 6 along its length, and the outlet 13 of the upper ventilation duct 7 is located in the middle of the inner wall of the shell 6.

[0022] One port of the lower ventilation duct 8 is located at the open end of the housing 6, and the other port of the lower ventilation duct 8 is located at the closed end of the housing 6.

[0023] Both the first motor 27 and the second motor 10 are servo motors.

[0024] The driven rod of the first cleaning rod 9 has a sliding groove 91 in the middle, and the working end of the first driving rod 14 is an arc working end, which is slidably located in the sliding groove 91; the other end of the first driving rod 14 is fixedly connected to the output shaft of the first motor 27, and the first motor 27 is fixedly installed in the mounting groove on the inner side wall of the housing 6.

[0025] The second sweeping rod 17 is a straight rod; one end of the intermediate connecting rod 16 is movably connected to the middle of the second sweeping rod 17, one end of the intermediate connecting rod 16 is movably connected to one end of the second driving rod 15, and the other end of the second driving rod 15 is fixedly connected to the output shaft of the second motor 10; when the second motor 10 is working, it drives the second sweeping rod 17 to reciprocate through the movement of the second driving rod 15 and the intermediate connecting rod 16.

[0026] The fan 19 is fixedly mounted on the rotating shaft 18. The input end of the rotating shaft 18 is fixedly connected to the output end of the fan motor 24, and the other end of the rotating shaft 18 is movably located at the bottom of the magnetic particle collection chamber 20.

[0027] The collection chamber 20 is a box with an open top. One side of the collection chamber 20, which corresponds to the inlet of the lower ventilation duct 8, has an air inlet 11 that connects to the lower ventilation duct 8. The bottom surface of the collection chamber 20 is provided with a bottom cover 25. The electromagnetic coil 21 is located on the inner side of the bottom cover 25. The bottom cover is opened to collect and clean the magnetic particles in the collection chamber 20.

[0028] The principle of magnetic particle collection in the disc brake of this invention is explained as follows:

[0029] (1) Establish an algorithm for generating magnetic induction intensity using an electromagnetic coil

[0030] Starting from the assumption of molecular circulation describing the magnetic medium, and combining it with the Biot-Savart law, the magnetic field of the electromagnetic coil is calculated. According to the surface current density formula, the magnetic field of the single rectangular coil in electromagnetic coil 21 is related to... Figure 20 The surface current density on any plane parallel to XOY is:

[0031]

[0032] In formula (1), h is the electromagnetic coil 21 as shown. Figure 20 The height along the Z direction is shown in meters (m); I represents the current intensity of the conductor in electromagnetic coil 21 in amperes (A); let (x1, y1, z1) represent a point on electromagnetic coil 21 to obtain the closed-plane current element of electromagnetic coil 21:

[0033] dI=αdz1 (2)

[0034] If each turn of the conductor in the electromagnetic coil 21 is considered as an independent current-carrying conductor, then the differentiation of each independent current-carrying conductor can be performed. If the independent current-carrying conductor is considered as a series of thin rectangular rings of thickness dz1 parallel to XOY, then the magnetic induction intensity generated by the current intensity αdz1 of the thin rectangular rings A'B'C'D' at a certain point P(x,y,z) outside the electromagnetic coil 21 is dB.

[0035] The current element A'B'C'D' on the thin rectangular ring is decomposed into four parts: A'B', B'C', C'D', and D'A'. According to the Biot-Savart law, taking A'B' as an example, x = a.

[0036]

[0037] In formula (3), a is the length of electromagnetic coil 21 in meters; b is the width of electromagnetic coil 21 in meters; μ0 is the permeability in vacuum in H / m; dB x(A'B') Let be the magnetic flux density along the x-direction produced at point P by a current element on segment A'B' of a thin rectangular ring dz1, in tons (T); dB. y(A'B') Let be the magnetic flux density along the y-direction produced at point P by a current element on segment A'B' of a thin rectangular ring dz1, in tons (T); dB. z(A'B') Let T be the magnetic flux density along the z-direction produced at point P by a current element on segment A'B' of a thin rectangular ring of length dz1.

[0038] Similarly, the dB value for segment B'C can be obtained. x(B'C') dB y(B'C') dB z(B'C') :

[0039]

[0040] In formula (4), dB x(B'C') Let be the magnetic flux density along the x-direction produced at point P by a current element on segment B'C' of a thin rectangular ring dz1, in tons (T); dB. y(B'C') Let be the magnetic flux density along the y-direction produced at point P by a current element on segment B'C' of a thin rectangular ring dz1, in tons (T); dB. z(B'C')Let T be the magnetic flux density along the z-direction produced at point P by a current element on segment B'C' of a thin rectangular ring of length dz1.

[0041] C'D' segment dB x(C'D') dB y(C'D') dB z(C'D') :

[0042]

[0043] In formula (5), dB x(C'D') Let be the magnetic flux density along the x-direction produced at point P by a current element on segment C'D' of a thin rectangular ring dz1, in tons (T); dB. y(C'D') Let be the magnetic flux density along the y-direction produced at point P by a current element on segment C'D' of a thin rectangular ring dz1, in tons (T); dB. z(C'D') Let T be the magnetic flux density along the z-direction produced at point P by a current element on segment C'D' of a thin rectangular ring of length dz1.

[0044] and D'A' segment dB x(D'A') dB y(D'A') dB z(D'A') :

[0045]

[0046] In the formula (6), dB x(D'A') Let be the magnetic flux density along the x-direction produced at point P by a current element on segment D'A' of a thin rectangular ring dz1, in tons (T); dB. y(D'A') Let be the magnetic flux density along the y-direction produced at point P by a current element on segment D'A' of a thin rectangular ring dz1, in tons (T); dB. z(D'A') Let T be the magnetic flux density along the z-direction produced at point P by a current element on segment D'A' of a thin rectangular ring of length dz1.

[0047] After obtaining the magnetic induction intensity produced by a single rectangular coil at point P, the magnetic induction intensity produced by a rectangular coil with N turns on surface A1B1B2A2 of the electromagnetic coil 21 at point P can be obtained as follows:

[0048]

[0049] In the formula (7), Let T be the magnetic flux density along the x-direction produced at point P by a rectangular coil with N turns on surface A1B1B2A2 of electromagnetic coil 21. Let T be the magnetic induction intensity along the y-direction produced at point P by a rectangular coil with N turns on surface A1B1B2A2 of electromagnetic coil 21. Let T be the magnetic flux density along the z-direction produced at point P by a rectangular coil with N turns on surface A1B1B2A2 of electromagnetic coil 21.

[0050] The magnetic induction intensity produced at point P by the rectangular coil with N turns on surface B1C1C2B2 of the electromagnetic coil 21 is:

[0051]

[0052] In the formula (8), Let T be the magnetic flux density along the x-direction produced at point P by a rectangular coil with N turns on surface B1C1C2B2 of electromagnetic coil 21. Let T be the magnetic flux density along the y-direction produced at point P by a rectangular coil with N turns on surface B1C1C2B2 of electromagnetic coil 21. Let T be the magnetic flux density along the z-direction produced at point P by a rectangular coil with N turns on surface B1C1C2B2 of electromagnetic coil 21.

[0053] The magnetic induction intensity produced at point P by the rectangular coil with N turns on the C1D1D2C2 surface of the electromagnetic coil 21 is:

[0054]

[0055] In the formula (9), Let T be the magnetic flux density along the x-direction produced at point P by a rectangular coil with N turns on the C1D1D2C2 surface of electromagnetic coil 21. Let T be the magnetic flux density along the y-direction produced at point P by a rectangular coil with N turns on the C1D1D2C2 surface of electromagnetic coil 21. Let T be the magnetic flux density along the z-direction produced at point P by a rectangular coil with N turns on the C1D1D2C2 surface of electromagnetic coil 21.

[0056] The magnetic induction intensity produced at point P by the rectangular coil with N turns on the D1A1A2D2 surface of the electromagnetic coil 21 is:

[0057]

[0058] In the formula (10), Let T be the magnetic flux density along the x-direction produced at point P by a rectangular coil with N turns on the D1A1A2D2 surface of electromagnetic coil 21. Let T be the magnetic flux density along the y-direction produced at point P by a rectangular coil with N turns on the D1A1A2D2 surface of electromagnetic coil 21. Let T be the magnetic flux density along the z-direction produced at point P by a rectangular coil with N turns on the D1A1A2D2 surface of electromagnetic coil 21.

[0059] Therefore, the formula for calculating the magnetic field generated by the electromagnetic coil 21 at point P is obtained:

[0060]

[0061]

[0062]

[0063]

[0064] In the formula (14), B x B represents the x-component of the magnetic field strength produced by electromagnetic coil 21 at point P, expressed in tons (T). y B represents the y-component of the magnetic field strength generated by electromagnetic coil 21 at point P, expressed in tons (T). z Let T be the component of the magnetic induction intensity produced by electromagnetic coil 21 at point P in the z-direction, in units of T; It is the vector of the total magnetic flux density generated by electromagnetic coil 21 at point P, in units of T.

[0065] (2) Establish a dynamic algorithm for the force exerted on particles in the channel.

[0066] The force on a magnetic particle in a magnetic field can be determined by the following formula:

[0067]

[0068] In the formula (15), F B S is the magnetic force experienced by the magnetic particle, in N; S is the area of ​​interaction between the magnetic field and the magnetic particle (if the magnetic particle is considered as a sphere, its area of ​​interaction is the area of ​​the largest circle in the cross-section), in m². 2 .

[0069] The formulas for calculating the magnetic force of a magnetic particle along the y-direction and along the z-direction in a magnetic field are as follows:

[0070]

[0071] The formula for calculating the force acting on a single spherical particle moving in a fluid (air) is:

[0072]

[0073] In the formula (17), ρ f The density of the fluid environment in which the spherical particles are located, expressed in kg / m³. 3 ;uf The velocity of the fluid at the location of the spherical particle, expressed in m / s; u p d represents the velocity of the spherical particle, measured in m / s. p C is the diameter of the spherical particle, in meters (m). D is the drag coefficient, which is a dimensionless quantity.

[0074] The formulas for calculating the forces acting on a single spherical particle moving in a fluid (air) along the y and z directions are as follows:

[0075]

[0076] The particles include magnetic particles and non-magnetic particles.

[0077] Drag coefficient C D The value can be determined by the following formula:

[0078]

[0079] In formula (19), R e Let be the Reynolds number, which is a dimensionless quantity. The value of the Reynolds number can be determined by the following formula:

[0080]

[0081] In the formula (20), μ is the dynamic viscosity coefficient of the fluid in which the spherical particle is located, and it is a dimensionless quantity.

[0082] (3) Establish an algorithm for the separation and analysis of non-magnetic particles

[0083] The free settling velocity or suspension velocity of spherical particles can be obtained from the following equilibrium equation:

[0084]

[0085] In the formula (21), ρ p Density of spherical particles, in kg / m³ 3 g is the acceleration due to gravity, with units of m / s². 2 ; The fluid resistance experienced by the spherical particle when it reaches equilibrium, expressed in N;

[0086] The commonly used formula for fluid resistance in fluid mechanics is:

[0087]

[0088] u = |u f -u p | (23)

[0089] In formula (22), u is the difference between the velocity of the spherical particle and the velocity of the fluid in which the spherical particle is located, in m / s. p The projected area of ​​the spherical particle on the plane perpendicular to the flow direction, in meters. 2 ;

[0090] For the spherical particles, there are

[0091]

[0092] Substituting equations (22) and (23) into equation (21) yields a general formula for calculating the applicable free settling velocity or suspension velocity:

[0093]

[0094] The corresponding C for each region D Substituting formula (14) into equation (25) yields:

[0095]

[0096] (4) Establish the equation of motion trajectory of the magnetic sphere particles

[0097] From equations (16) and (18), the forces acting on the spherical magnetic particles in the device of this invention can be obtained as follows:

[0098]

[0099] According to Newton's second law F = ma, transforming equation (27) yields the equation for the trajectory of the spherical magnetic particle along the y-direction:

[0100] y direction:

[0101]

[0102] In the formula (28), This represents the component of the velocity of the spherical magnetic particle in the y-direction, with units of m / s; This represents the component of the airflow velocity in the y-direction, expressed in m / s.

[0103] According to Newton's second law F = ma, transforming equation (27) yields the equation for the trajectory of the spherical magnetic particle along the z-direction:

[0104] z-direction:

[0105]

[0106] In the formula (29), This represents the component of the airflow velocity in the z-direction, with units of m / s. This represents the z-component of the velocity of the spherical magnetic particle, expressed in m / s.

[0107] (5) Fitting the current control function

[0108] Equations (11), (12), and (13) are simplified as follows:

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115] Combining equations (28) and (32), we get:

[0116]

[0117] Combining equations (29) and (33), we get:

[0118]

[0119] Assuming the magnetic particles enter the particle separation section from the cleaning channel 12 at a height H, and the time t1 elapses from entry to when the particles are just cleaned and collected in the collection chamber 20 by the magnetic particle cleaning mechanism, the particle's path length in the Y direction is ΔY; and the particle's path length in the Z direction is ΔZ, then the following relationship can be obtained:

[0120]

[0121] In the formula (38), The initial velocity of the magnetic particle along the Y direction when it enters the device is denoted as . The initial velocity of the magnetic particle in the Z direction when it enters the device. According to equations (36) and (37), the velocities of the magnetic particle in the y and z directions within the device are both functions related to the current I of the electromagnetic coil 21.

[0122] After modeling the trajectory equation of the magnetic sphere in Matlab, the following control function can be obtained by fitting according to formulas (36) and (38):

[0123]

[0124] In formula (39), I is the current in the conductor of the ring-shaped electromagnetic coil 21, in A, u c The current vehicle speed is expressed in m / s.

[0125] The beneficial technical effects of this invention are reflected in the following aspects:

[0126] (1) The active separation mechanism for magnetic and non-magnetic particles of the present invention has an outlet 13 of an upper ventilation duct 7 in the middle of the inner wall of the housing 6. When the car is in motion, the air entering from the upper ventilation duct 7 increases the efficiency of the pair of first cleaning rods 9 in cleaning the abrasive particles of the brake disc 2 and causes the particles to fall into the cleaning channel 12. The first cleaning rods 9 can make the particles on the brake disc leave the disc surface quickly, ensuring the braking performance of the brake disc, reducing the wear of the brake disc, and increasing the service life of the brake disc.

[0127] (2) After the particles enter the cleaning channel 12, the electromagnetic coil 21 and the fan 19 work together to actively separate the magnetic and non-magnetic particles. Magnetic particles enter the collection chamber 20, while non-magnetic particles leave the device. Compared with cyclone collectors, it has better collection efficiency for particles with a diameter of less than 36 micrometers, and can still achieve an 80% collection rate for particles with a diameter of 80 micrometers that are uniformly distributed in the air.

[0128] (3) The fan 19 in the active separation mechanism of magnetic and non-magnetic particles of the present invention is mounted on the rotating shaft 18 and rotated by the fan motor 24 to provide upward air resistance. The fan 19 only needs to provide fluid resistance for separating magnetic and non-magnetic particles, and has low energy consumption. It can effectively separate magnetic and non-magnetic particles with the device of the present invention under low energy consumption.

[0129] (4) The present invention provides a method for separating magnetic particles from non-magnetic particles. It provides a method for separating particles by controlling the first motor 27, the second motor 10 and the fan motor 24 according to the vehicle driving status during particle recovery, and a formula for adjusting the current of the electromagnetic coil according to the current vehicle speed. By controlling the current of the electromagnetic coil, the magnetic field generated by the electromagnetic coil is controlled, thereby separating and collecting magnetic particles more efficiently.

[0130] (5) The active separation mechanism for magnetic and non-magnetic particles of the present invention is easy to install and disassemble on vehicles. The open design does not affect the cooling of the brake pair. Furthermore, the present invention can be combined with various disc brakes, not limited to solid discs or ventilated discs, and can be applied to a variety of vehicle models, thus having wide applicability. Attached Figure Description

[0131] Figure 1 This is a schematic diagram of the device structure of the present invention;

[0132] Figure 2 for Figure 1 A schematic diagram of the rear view structure;

[0133] Figure 3 This is a schematic diagram of the shell structure;

[0134] Figure 4 for Figure 3 A bottom view;

[0135] Figure 5 A cross-sectional view of the structure of the mechanism for actively separating magnetic and non-magnetic particles;

[0136] Figure 6 for Figure 5 A magnified view of a portion of the image;

[0137] Figure 7 for Figure 4 The right view;

[0138] Figure 8 for Figure 7 AA section view;

[0139] Figure 9 A schematic diagram of the brake disc cleaning mechanism;

[0140] Figure 10 for Figure 7 BB section view;

[0141] Figure 11 for Figure 10 A magnified view of a section at point A in the middle;

[0142] Figure 12 for Figure 10 A magnified view of a section at point B in the middle;

[0143] Figure 13 for Figure 10 CC section view;

[0144] Figure 14 for Figure 10 DD sectional view;

[0145] Figure 15 This is a schematic diagram of the mechanical principle of a magnetic particle cleaning mechanism.

[0146] Figure 16 A schematic diagram of the mechanical principle of the brake disc particle cleaning mechanism;

[0147] Figure 17 The control function of equation (39) and the fitting sampling points in multiple simulations;

[0148] Figure 18 For particle size analysis report;

[0149] Figure 19 This is a force analysis diagram of the particles;

[0150] Figure 20 This is a schematic diagram of the permanent magnet used in this invention;

[0151] Figure 21 The simulation diagram of the overall flow field of the device at a vehicle speed of 5 m / s;

[0152] Figure 22 This is a velocity contour plot of a certain cross section of the device;

[0153] Figure 23 The velocity cloud map inside the particle separation unit when the vehicle speed is 5 m / s;

[0154] Figure 24 This is a post-processing rate diagram obtained from the post-processing of the particle separation section;

[0155] Figure 25 The trajectory of the magnetic particles in the vertical plane within the particle separation device under defined conditions;

[0156] Figure 26 The graph shows the result of how the device's collection efficiency changes with increasing particle diameter.

[0157] Figure 1-16 The components listed are: 1. Brake caliper; 2. Disc brake; 3. Steering knuckle; 4. Mounting fork arm; 5. Mounting positioning hole; 6. Housing; 7. Upper ventilation duct; 8. Lower ventilation duct; 9. First cleaning rod; 27. First motor; 11. Separating fan inlet; 12. Cleaning channel; 13. Upper outlet; 14. First drive rod; 15. Second drive rod; 16. Intermediate connecting rod; 17. Second cleaning rod; 18. Rotating shaft; 19. Fan; 20. Magnetic particle collection chamber; 21. Electromagnetic coil; 22. Inclined surface; 23. Motor chamber; 24. Fan motor; 25. Bottom cover; 10. Second motor; 91. Sliding groove. Detailed Implementation

[0158] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0159] Example 1

[0160] See Figure 1 and Figure 2 A disc brake with an active separation mechanism for magnetic and non-magnetic particles, the disc brake including a brake disc 2, a brake caliper 1 and a steering knuckle 3, and also including an active separation mechanism for magnetic and non-magnetic particles.

[0161] See Figure 5 The active separation mechanism for magnetic and non-magnetic particles includes a housing 6, a pair of brake disc cleaning mechanisms, a magnetic particle cleaning mechanism, and a fan mechanism.

[0162] See Figure 3 and Figure 4 The casing 6 is a long, flat box with an open top, see [reference]. Figure 1 The lower part of the brake disc 2 is located inside the housing 6.

[0163] See Figure 4 The shell 6 has a closed end along its length and an open end. Upper ventilation channels 7 are formed on both side walls of the open end of the shell 6, and these upper ventilation channels 7 are parallel to the bottom surface of the shell 6. (See also...) Figure 5 The inlet of the upper ventilation duct 7 is located at the open end of the shell 6 along its length, and the outlet 13 of the upper ventilation duct 7 is located in the middle of the inner wall of the shell 6.

[0164] See Figure 5 The inner side of the other end of the shell 6 along the length direction is an inclined surface 22 that slopes towards the open end; a cleaning channel 12 is provided in the length direction of the shell 6 below the inclined surface 22, the cleaning channel 12 is parallel to the bottom surface of the shell 6 and passes through the closed end of the shell 6.

[0165] See Figure 5 The bottom of the housing 6 has a lower ventilation duct 8 along its length, which is located parallel to the cleaning channel 12 below it. One end of the lower ventilation duct 8 is located at the open end of the housing 6, and the other end of the lower ventilation duct 8 is located at the closed end of the housing 6.

[0166] See Figure 5 , Figure 10 and Figure 12 The inner sides of the housing 6 have recessed mounting grooves in the middle of their respective side walls. A pair of brake disc cleaning mechanisms are symmetrically arranged in the mounting grooves. The different movement states of the brake disc cleaning mechanisms are shown in [the diagram]. Figure 16 .

[0167] See Figure 7 , Figure 8 and Figure 9 The brake disc cleaning mechanism includes a first cleaning rod 9, a first driving rod 14, and a first motor 27 connected in sequence. The first cleaning rod 9 is a T-shaped rod, with the horizontal bar being the cleaning rod and the vertical bar being the driven rod. The outer end of the driven rod is hinged and installed in a mounting groove on the inner wall of the housing 6. A sliding groove 91 is provided in the middle of the driven rod, and the working end of the first driving rod 14 is an arc-shaped working end, which slides within the sliding groove 91. The other end of the first driving rod 14 is fixedly connected to the output shaft of the first motor 27, which is fixedly installed in the mounting groove on the inner wall of the housing 6. Figure 14 The first motor 27 is a servo motor. During operation, the first motor 27 drives the cleaning rod of the first sweeping rod 9 to move back and forth through the swing of the first drive rod 14.

[0168] See Figure 6The magnetic particle cleaning mechanism includes a second cleaning rod 17, an intermediate connecting rod 16, a second driving rod 15, and a second motor 10 connected in sequence. The second cleaning rod 17 is a straight rod. One end of the intermediate connecting rod 16 is movably connected to the middle of the second cleaning rod 17, and the other end of the intermediate connecting rod 16 is movably connected to one end of the second driving rod 15. The other end of the second driving rod 15 is fixedly connected to the output shaft of the second motor 10. The second cleaning rod 17, the intermediate connecting rod 16, and the second driving rod 15 constitute a planar linkage mechanism located on the bottom surface within the cleaning channel 12. The second motor 10 is fixedly installed at the top within the cleaning channel 12. The second motor 10 is a servo motor. During operation, the second motor 10 drives the reciprocating movement of the second cleaning rod 17 through the movement of the second driving rod 15 and the intermediate connecting rod 16. Different motion states of the planar linkage mechanism are shown in [details omitted]. Figure 15 .

[0169] See Figure 10 and Figure 14 A magnetic particle collection chamber 20 is installed in the lower ventilation duct 8 below the middle of the cleaning channel 12. (See also...) Figure 13 The collection chamber 20 is a box with an open top. See also Figure 6 An air inlet 11, connecting to the lower ventilation duct 8, is provided on one side of the collection chamber 20, corresponding to the inlet of the lower ventilation duct 8. An electromagnetic coil 21 and a bottom cover 25 are installed on the bottom surface of the collection chamber 20. The bottom cover 25 is opened for the recovery and cleaning of magnetic particles in the collection chamber 20.

[0170] See Figure 11 and Figure 13 The fan mechanism includes a fan 19 and a fan motor 24. The fan 19 is fixedly mounted on a rotating shaft 18, the input end of which is fixedly connected to the output end of the fan motor 24, and the other end of the rotating shaft 18 is movably mounted at the bottom of the magnetic particle collection chamber 20. The fan 19 is located inside the magnetic particle collection chamber 20, and the fan motor 24 is fixedly mounted at the top of the cleaning channel 12.

[0171] See Figure 17 The active control function is modeled in Matlab using active control steps. The horizontal axis represents the current vehicle speed, and the vertical axis represents the current in the conductor of the electromagnetic coil of the active control. The multiple points in the figure are sampling points when fitting the function.

[0172] See Figure 18 The brake particles generated on the disc brake were obtained by conducting a braking test on the brake pair in the laboratory, as shown in the figure. In this invention, the particle data is determined by the particle size analysis report.

[0173] See Figure 19 To facilitate the analysis of the motion state of the spherical particles, a force analysis diagram of the spherical particles during the separation process is provided. This is the component of the air resistance force experienced by the spherical particle in the device along the z-direction; This is the component of the air resistance experienced by the spherical particle in the device along the y-direction; This is the component of the magnetic force experienced by the spherical particle in the device along the y-direction; σ is the magnetic force exerted on the spherical particle along the z-direction within the device; mg is the gravitational force on the spherical particle.

[0174] See Figure 20 The coordinate system used for calculating and analyzing the magnetic induction intensity of electromagnetic coil 21 is shown in the figure. This coordinate system is also the parameter coordinate system of the device of this invention.

[0175] See Figure 21 and Figure 22 The device of the present invention was installed on a car, with the fan 19 rotating at 600 rpm. The simulation assumed the car was braking at high speed and then decelerating to continue moving at 5 m / s. The overall flow field simulation of the device installed on the car was obtained. The gas velocity at the inclined plane 22 is relatively low, allowing particles to effectively converge in the cleaning channel 12.

[0176] See Figure 23 and Figure 24 The device of the present invention is installed on a car, the fan 19 is rotated at 600 rpm, and the car is assumed to be braking and decelerating to continue moving forward at a speed of 5 m / s while driving at high speed. The flow field diagram of the device of the present invention when separating particles is obtained. When the car is moving, in conjunction with the fan 19, the magnetic particle collection part can make non-magnetic particles leave the magnetic particle collection part.

[0177] The working principle of the device of the present invention is explained as follows:

[0178] When the vehicle is stationary, the fan motor 24, the first motor 27 and the second motor 10 stop working and the electromagnetic coil is de-energized.

[0179] When the vehicle starts, the fan motor 24 starts working, and the second motor 10 starts working. The fan motor 24 drives the separation fan 19 to rotate through the rotating shaft, providing lift for the particles. The second motor 10 drives the second sweeping rod 17 to reciprocate through the second active rod 15 and the intermediate connecting rod 16 to sweep the particles located on the sweeping channel 12. Based on the current vehicle speed, the real-time control current I of the electromagnetic coil 21 is calculated and controlled.

[0180] When the vehicle brakes during operation, the first motor 27 and the second motor 10 start working. The first motor 27 controls the first drive rod 14 to rotate, driving the first sweeping rod 9 from position S2 to position S1 to sweep the particles generated by braking friction on the brake disc. The second motor 10 drives the second sweeping rod 17 to reciprocate through the second drive rod 15 and the intermediate connecting rod 16 to sweep the particles located on the sweeping channel 12. The controller reads the vehicle speed signal from the vehicle speed sensor, calculates and controls the real-time control current I of the electromagnetic coil 21.

[0181] See Figure 16 When the vehicle stops braking, the first motor 27 rotates and drives the first active rod 14 to move the first sweeping rod from position S1 to S2. After a 10-second delay, the second motor stops working and calculates and controls the real-time control current I of the electromagnetic coil 21 according to the current vehicle speed.

[0182] This device is equipped with a fan 19 for separating magnetic and non-magnetic particles. The fan motor 24 controls the speed of the fan 19 to provide upward air resistance. Magnetic particles entering the collection chamber 20 are partially moved downwards into the collection chamber 20 due to gravity, air resistance, and magnetic force, while the remaining magnetic particles fall into the cleaning channel 12. The second cleaning rod 17, driven by the second motor 10, reciprocates and is then swept into the collection chamber 20. Non-magnetic particles are separated by gravity, air resistance, and the upward resistance generated by the separating fan 19. They are not collected in the magnetic particle collection chamber 20 but instead enter the cleaning channel 12 below the closed end of the housing 6 and are discharged through the cleaning channel 12.

[0183] Example 2

[0184] The following is a detailed explanation of the collection of magnetic particles in disc brakes:

[0185] The particle size d of the brake disc of disc brake 2 p Taking 5*10^-5m as an example, the specific parameters of the device of the present invention are as follows: vacuum permeability μ0 = 4π*10^-7H / m, air density ρ f =1.29kg / m 3 Magnetic particle density ρ p =7*10^3 kg / m 3 The dynamic viscosity coefficient of air is μ = 1.79 × 10⁻⁵, and the acceleration due to gravity is g = 9.81 m / s². 2 The rectangular electromagnetic coil has 150 turns N, a length a = 0.02m, a width b = 0.02m, a height h = 0.005m, and a control current I = 0.149A (retaining three significant figures).

[0186] (1) Establishing an algorithm for the magnetic induction intensity of an electromagnetic coil

[0187] According to the surface current density formula, the single rectangular coil in electromagnetic coil 21 and... Figure 21 The surface current density on any plane parallel to XOY is:

[0188]

[0189] Therefore, the closed-plane current element of electromagnetic coil 21 can be obtained.

[0190]

[0191] According to the Biot-Savart law, the magnetic field strength along the x, y, and z directions produced by the current element at point P on segment A'B' can be obtained, where x = 0.02.

[0192]

[0193] Similarly, the dB value for segment B'C can be obtained. x(B'C') dB y(B'C') dB z(B'C') :

[0194]

[0195] C'D' segment dB x(C'D') dB y(C'D') dB z(C'D' ):

[0196]

[0197] and D'A' segment dB x(D'A') dB y(D'A') dB z(D'A') :

[0198]

[0199] After obtaining the magnetic induction intensity produced by a single rectangular coil at point P, the magnetic induction intensity produced by a rectangular coil with N turns on surface A1B1B2A2 of the electromagnetic coil 21 at point P can be obtained as follows:

[0200]

[0201] The magnetic induction intensity produced at point P by the rectangular coil with N turns on surface B1C1C2B2 of the electromagnetic coil 21 is:

[0202] The magnetic induction intensity produced at point P by the rectangular coil with N turns on the C1D1D2C2 surface of the electromagnetic coil 21 is:

[0203] The magnetic induction intensity produced at point P by the rectangular coil with N turns on the D1A1A2D2 surface of the electromagnetic coil 21 is:

[0204]

[0205] Therefore, we can obtain the formula for calculating the magnetic field generated by the electromagnetic coil 21 at point P:

[0206]

[0207]

[0208]

[0209]

[0210] (2) Establish a dynamic algorithm for the force exerted on particles in the channel.

[0211] The magnetic force on the magnetic particles is:

[0212]

[0213] The formulas for calculating the forces acting on a magnetic particle in the magnetic field along the y-direction and the z-direction are as follows:

[0214]

[0215] The formula for calculating the force acting on a single spherical particle moving in a fluid (air) is:

[0216]

[0217] The formulas for calculating the forces acting on a single spherical particle moving in a fluid (air) along the y and z directions are as follows:

[0218]

[0219] C D The value can be determined by the following formula:

[0220]

[0221] The value of the Reynolds number can be determined by the following formula:

[0222]

[0223] (3) Establish an algorithm for the separation and analysis of non-magnetic particles

[0224] The free settling velocity or suspension velocity of spherical particles can be obtained from the following equilibrium equation:

[0225]

[0226] The fluid resistance formula here is:

[0227]

[0228] u = |u f -u p | (23)

[0229] For the spherical particles, we have:

[0230]

[0231] Substituting equations (19) and (18) into equation (17) yields a general formula for calculating the applicable free settling velocity or suspension velocity:

[0232]

[0233] The corresponding C for each region D Substituting formula (10) into the equation yields:

[0234]

[0235] (4) Establish the equation of motion trajectory of the magnetic spherical particle

[0236] From equations (16) and (18), the forces acting on the spherical magnetic particles in the device of this invention can be obtained as follows:

[0237]

[0238] The kinetic equations of the magnetic particles in this device can be obtained:

[0239] y direction:

[0240]

[0241] z-direction:

[0242]

[0243] (5) Fitting the current control function

[0244] Equations (11), (12), and (13) are simplified as follows:

[0245]

[0246]

[0247]

[0248]

[0249]

[0250]

[0251] Combining equations (28) and (32), we get:

[0252]

[0253] Combining equations (29) and (33), we get:

[0254]

[0255] Assuming the magnetic particles enter the particle separation section from the cleaning channel 12 at a height H, and the time t1 elapsed from entry to when the particles are just cleaned and collected in the collection chamber 20 has a path length of ΔY in the Y direction and a path length of ΔZ in the Z direction, we can obtain the following relationship:

[0256]

[0257] According to equations (36) and (37), the velocities of the magnetic particles in the Y and Z directions within the device are both functions related to the current I of the loop coil.

[0258] After modeling the trajectory equation of the magnetic sphere in Matlab, the following control function can be obtained by fitting according to formulas (36) and (38):

[0259] I = 0.000125 * 5 3 -0.00283*5 2 +0.04685-0.03=0.148875≈0.149 (39)

[0260] See Figure 25 The device of this invention is installed on a car. The fan 19 rotates at 600 rpm. Assuming the car brakes at high speed and decelerates to continue moving at 5 m / s, the resulting particle size is d. p =5*10^-5m, and from Figure 20The particles enter the device horizontally at a height of 0.034m in the coordinate system for particle separation, simulating the motion of the particles in the vertical plane YOZ during separation using the device of this invention. Using the data described in Example 2 as hypothetical data, the motion of the magnetic particles is analyzed using the flow field data of the magnetic particle collection section obtained through simulation, based on the differential method. The origin of the coordinate system is... Figure 20 The origin of the coordinate system on the electromagnetic coil 21 is [-0.02, 0.0225] in the X direction of the magnetic particle collection cavity 20, and the cleaning range of the second cleaning rod 17 is [0.0075, 0.0285]. Therefore, when the particles move to the inlet height Z = 0.016 of the collection cavity, all particles in the X coordinate range of [-0.02, 0.0285] can be collected into the collection cavity 20.

[0261] By changing the particle size and repeating the simulation, we can obtain... Figure 26 The diagram shows the collection efficiency of the device of the present invention for particles of different diameters.

[0262] See Figure 26 Assuming that the magnetic particles are uniformly distributed in the cleaning channel 12 and move horizontally at a speed of 5 m / s, the particle size of the magnetic particles is changed, and the collection efficiency of the device of the present invention is obtained through analysis. This simulation result is obtained under the premise that the magnetic particles are uniformly distributed in space. However, in reality, the magnetic particles mainly gather closer to the bottom surface of the cleaning channel 12, so the actual collection efficiency is higher.

[0263] like Figure 24 and Figure 25 As shown, the device of the present invention can effectively separate magnetic and non-magnetic particles, allowing magnetic particles to enter the magnetic particle collection chamber 20, while non-magnetic particles, after entering the cleaning channel 12 below the closed end of the housing 6, move with the airflow and are discharged through the cleaning channel 12. Figure 25 and Figure 26 The device of the present invention can effectively collect magnetic particles generated by vehicle braking. It can effectively collect magnetic particles with a particle size of less than 36 micrometers and also has good collection efficiency for magnetic particles with a particle size of 80 micrometers.

Claims

1. A disc brake with an active mechanism for separating magnetic and non-magnetic particles, the disc brake comprising a brake disc (2), a brake caliper (1), and a steering knuckle (3), characterized in that: It also includes a mechanism for actively separating magnetic and non-magnetic particles; The active separation mechanism for magnetic and non-magnetic particles includes a housing (6), a pair of brake disc cleaning mechanisms, a magnetic particle cleaning mechanism, and a fan mechanism; The shell (6) is a long, flat box with an open top; The lower part of the brake disc (2) is located inside the housing (6); One end of the shell (6) along its length is a closed end, and the other end is an open end; Upper ventilation channels (7) are respectively provided on the two side walls of the open end of the shell (6), and the upper ventilation channels (7) are parallel to the bottom surface of the shell (6); The inner side of the other end of the shell (6) along the length direction is an inclined surface (22) that slopes towards the open end; a cleaning channel (12) is provided in the length direction of the shell (6) below the inclined surface (22), the cleaning channel (12) is parallel to the bottom surface of the shell (6) and passes through the closed end of the shell (6); The bottom of the housing (6) is provided with a lower ventilation duct (8) along its length, and the lower ventilation duct (8) is located parallel to the bottom of the cleaning channel (12); The inner sides of the housing (6) are respectively provided with recessed mounting grooves, and a pair of brake disc cleaning mechanisms are symmetrically arranged in the mounting grooves; The brake disc cleaning mechanism includes a first cleaning rod (9), a first driving rod (14), and a first motor (27) connected in sequence; the first cleaning rod (9) is a T-shaped rod, wherein the horizontal rod is a cleaning rod and the vertical rod is a driven rod; the outer end of the driven rod is hinged and installed in the mounting groove; the working end of the first driving rod (14) is in contact with the middle of the driven rod, and the other end of the first driving rod (14) is fixedly connected to the output shaft of the first motor (27); when the first motor (27) is working, the cleaning rod of the first cleaning rod (9) is driven to move back and forth by the swing of the first driving rod (14); The cleaning rods of the pair of first cleaning rods (9) of the pair of brake disc cleaning mechanisms contact the two sides of the brake disc respectively; The magnetic particle cleaning mechanism includes a second cleaning rod (17), an intermediate connecting rod (16), a second driving rod (15), and a second motor (10) connected in sequence; wherein the second cleaning rod (17), the intermediate connecting rod (16), and the second driving rod (15) constitute a planar linkage mechanism, the planar linkage mechanism is located on the bottom surface inside the cleaning channel (12), and the second motor (10) is fixedly installed at the top inside the cleaning channel (12); A magnetic particle collection chamber (20) is provided in the lower ventilation duct (8) below the middle of the cleaning channel (12), and an electromagnetic coil (21) is provided on the bottom surface of the magnetic particle collection chamber (20). The fan mechanism includes a fan (19) and a fan motor (24); the fan (19) is located in the magnetic particle collection chamber (20) of the lower ventilation duct (8), and the fan motor (24) is fixedly installed at the top of the cleaning channel (12).

2. The disc brake with an active mechanism for separating magnetic and non-magnetic particles according to claim 1, characterized in that: The inlet of the upper ventilation duct (7) is located at the open end of the shell (6) along its length, and the outlet (13) of the upper ventilation duct (7) is located in the middle of the inner wall of the shell (6).

3. A disc brake with an active mechanism for separating magnetic and non-magnetic particles according to claim 1, characterized in that: One port of the lower ventilation duct (8) is located at the open end of the housing (6), and the other port of the lower ventilation duct (8) is located at the closed end of the housing (6).

4. A disc brake with an active mechanism for separating magnetic and non-magnetic particles according to claim 1, characterized in that: Both the first motor (27) and the second motor (10) are servo motors.

5. A disc brake with an active mechanism for separating magnetic and non-magnetic particles according to claim 1, characterized in that: The driven rod of the first cleaning rod (9) has a sliding groove (91) in the middle. The working end of the first driving rod (14) is an arc working end, which is slidably located in the sliding groove (91). The other end of the first driving rod (14) is fixedly connected to the output shaft of the first motor (27), which is fixedly installed in the mounting groove on the inner side wall of the housing (6).

6. A disc brake with an active mechanism for separating magnetic and non-magnetic particles according to claim 1, characterized in that: The second sweeping rod (17) is a straight rod; one end of the intermediate connecting rod (16) is movably connected to the middle part of the second sweeping rod (17), one end of the intermediate connecting rod (16) is movably connected to one end of the second driving rod (15), and the other end of the second driving rod (15) is fixedly connected to the output shaft of the second motor (10); when the second motor (10) is working, it drives the second sweeping rod (17) to reciprocate through the movement of the second driving rod (15) and the intermediate connecting rod (16).

7. A disc brake with an active mechanism for separating magnetic and non-magnetic particles according to claim 1, characterized in that: The fan (19) is fixedly mounted on a rotating shaft (18), the input end of which is fixedly connected to the output end of the fan motor (24), and the other end of the rotating shaft (18) is movably located at the bottom of the magnetic particle collection chamber (20).

8. A disc brake with an active mechanism for separating magnetic and non-magnetic particles according to claim 1, characterized in that: The collection chamber (20) is a box with an open top. One side of the collection chamber (20) corresponding to the inlet of the lower ventilation duct (8) is provided with an air inlet (11) that connects to the lower ventilation duct (8). The bottom surface of the collection chamber (20) is provided with a bottom cover (25). The electromagnetic coil (21) is located on the bottom surface of the collection chamber (20). The bottom cover is opened to collect and clean the magnetic particles in the collection chamber (20).

Images