A self-enhancing magnetorheological fluid brake device

Abstract

The present invention discloses a self-enhancing magnetorheological fluid brake device, comprising a housing, an axle and a brake shaft, wherein the axle is arranged in the brake shaft and rotates together, wherein the housing is surrounded by left and right bottom plates and side plates to form a cylindrical working chamber, wherein the axle and the brake shaft are arranged in the working chamber through the left and right bottom plates, wherein two groups of symmetrical magnetorheological brake units and a sealing cylinder are also arranged in the working chamber, wherein the sealing cylinder is centered on the brake shaft and is arranged between the two groups of magnetorheological brake units. The present invention utilizes the magnetic field generated by the coil to directly act on the magnetorheological fluid, wherein the magnetorheological fluid in the sealed chamber is magnetized and instantly changes from liquid to solid, thereby connecting the brake shaft with the rotating disk, wherein the rotating disk drives the transmission wheel to rotate in the opposite direction, wherein the transmission wheel generates a braking pressure on the disk pressure block when rotating, thereby causing all the pressure modules to reverse as a whole, thereby pressurizing the magnetorheological fluid in the sealed chamber, thereby increasing the braking torque of the magnetorheological fluid on the brake disk.

Description

Technical Field

[0001] The invention belongs to the field of automobile braking, and in particular relates to a self-enhancing magnetorheological fluid braking device. Background Art

[0002] Magnetorheological fluids are widely used in aerospace / machining / construction / medical fields due to their fast response (millisecond level), low energy consumption, easy control, good durability, wide operating temperature range and long service life.

[0003] The characteristics of magnetorheological fluid can be used to conveniently manufacture brake devices, but currently the brake devices manufactured by magnetorheological fluid can only use its shear stress and the braking force it can generate is relatively small, so it cannot meet the braking requirements of large equipment such as new energy vehicles. For example, patent No. 201110460484.4 discloses a conical extrusion-shearing magnetorheological clutch, in which an iron core input disc is fixed at the front end of the input shaft, and an armature output disc that slides axially is provided at the front end of the output shaft, or an armature input disc that slides axially is provided at the front end of the input shaft, and an iron core output disc is fixed at the front end of the output shaft, and a cavity is formed between the iron core input disc and the armature output disc, and the cavity is filled with magnetorheological fluid, and a sealing ring that seals the magnetorheological fluid in the cavity is provided on the periphery of the cavity, and a coil that drives the armature output disc to move axially toward the iron core input disc is also provided in the working cavity, and an adjusting device for adjusting the volume of the cavity is also provided between the iron core input disc and the armature output disc. The advantages of this invention are: when the clutch is in working state, the magnetic field generated by the coil is used to attract the armature output disk, thereby reducing the volume of the cavity, and at the same time generating extrusion and shearing force on the magnetorheological fluid, which can transmit a larger torque, and has a small volume, reliable performance, compact structure and good effect. However, the armature used in the clutch of this invention is large and heavy, which is not conducive to the lightweight production of the brake device. Summary of the invention

[0004] The purpose of the present invention is to solve the above technical problems and provide a self-enhancing magnetorheological fluid brake device with light weight and large braking torque.

[0005] To achieve the above-mentioned purpose, the technical solution of the present invention is:

[0006] A self-amplifying magnetorheological fluid brake device comprises a shell, an axle and a brake shaft, wherein the axle is arranged in the brake shaft and rotates together, the shell is surrounded by left and right bottom plates and side plates to form a cylindrical working chamber, the axle and the brake shaft are arranged in the working chamber through the left and right bottom plates, and two groups of symmetrical magnetorheological brake units and a sealing cylinder are also arranged in the working chamber, the sealing cylinder is centered on the brake shaft and is arranged between the two groups of magnetorheological brake units, the magnetorheological brake unit comprises a magnetic conductive module, a rotating disk, a plurality of transmission gears and a pressurizing module, the magnetic conductive module and the rotating disk are arranged in sequence from the outside to the inside with the brake shaft as the center, the magnetic conductive module is arranged on the brake shaft, a gear-shaped inner cavity is provided in the center of the rotating disk, and a first ring which is engaged with the sealing cylinder and can rotate relatively is provided on the outer ring of the gear-shaped inner cavity shaped groove, and the magnetic conductive module, rotating disk and sealing cylinder are assembled to form a sealed cavity for containing magnetorheological fluid; a fixing strip is provided on the side of the sealing cylinder, and the sealing cylinder is fixedly connected to the side plate through the fixing strip, so that the sealing cylinder and the rotating disk are suspended and positioned; the outer ring of the rotating disk is set as a gear structure, and the transmission gears are evenly distributed on the outer ring of the rotating disk and meshed with it, and a gear fixing rod is provided at the center of each transmission gear, and the gear fixing rod is fixedly connected to the corresponding bottom plate; the pressurizing modules are respectively arranged on the same side of the transmission gear, and the pressurizing modules are composed of a disk pressurizing block, a connecting rod and a shaft pressurizing block connected in sequence, the disk pressurizing block is arranged next to the transmission gear, and the disk pressurizing block is provided with serrations meshing with the transmission gear, and the connecting rod is inserted into the sealing cavity from the side of the sealing cylinder and clamped on the sealing cylinder through the shaft pressurizing block.

[0007] As a further technical solution, the rotating disk and the corresponding bottom plate are each provided with a spring fixing rod, and a force limiting spring is provided between the two spring fixing rods.

[0008] As a further technical solution, the above-mentioned magnetic conductive module includes a magnetic conductive cavity, a magnetic isolation ring and a coil. The magnetic conductive cavity is a cylindrical cavity surrounded by a first magnetic conductive ring, a second magnetic conductive ring, a third magnetic conductive ring and a fourth magnetic conductive ring. The first magnetic conductive ring is an inner ring of the cylindrical cavity, the second magnetic conductive ring is arranged on the outer side surface of the first magnetic conductive ring, and the third magnetic conductive ring and the fourth magnetic conductive ring are the left and right bottom surfaces of the cylindrical cavity; the first magnetic conductive ring and the third magnetic conductive ring are installed on the brake shaft, and the magnetic isolation ring is clamped between the fourth magnetic conductive ring and the first magnetic conductive ring.

[0009] As a further technical solution, the fixing strips mentioned above are symmetrically arranged on the side of the sealing cylinder with the sealing cylinder as the center.

[0010] As a further technical solution, an annular protrusion is provided on the side of the above-mentioned first annular groove, and a second annular groove that is clamped with the annular protrusion is provided at the connection between the sealing cylinder and the rotating disk.

[0011] As a further technical solution, the sealing cylinder is horizontally divided into two symmetrical halves.

[0012] As a further technical solution, the connecting rod mentioned above is a cylinder.

[0013] As a further technical solution, the above-mentioned disc pressure block is L-shaped, and the transmission gear is located at the bend of the L-shape; the length and width of the shaft pressure block are both larger than the diameter of the hole through which the connecting rod is inserted on the sealing cylinder, and the surface of the shaft pressure block facing the brake shaft is set to an arc surface with the same arc as the brake shaft.

[0014] As a further technical solution, the pulling force of the force-limiting spring on the rotating disk is greater than the force of the magnetorheological fluid driving the rotating disk to rotate in the non-magnetized state, and is less than the force of the magnetorheological fluid driving the rotating disk to rotate in the magnetized state.

[0015] As a further technical solution, the number of transmission gears of each set of magnetorheological brake units is set to 4, and the number of pressurizing modules is set to 4.

[0016] As a further technical solution, the braking device also includes a coil current control module, which includes an external controller, a control circuit and an output circuit including a coil, the external controller is electrically connected to the input end of the control circuit, and the output end of the control circuit is electrically connected to the output circuit.

[0017] As a further technical solution, the external controller mentioned above adopts a PLC or a microcontroller.

[0018] As a further technical solution, the control circuit described above includes a power supply VCC, a three-terminal voltage regulator U2, a capacitor C1, a capacitor C2, a chip, and resistors R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10. The three-terminal voltage regulator U2 adopts AMS1117-5v, and the chip adopts L9349LF. The VIN pin of the three-terminal voltage regulator U2 is connected to the power supply VCC, the VOUT (TAB) pin of the three-terminal voltage regulator U2 is connected to the VS pin of the chip, and the capacitor C1 and the capacitor C2 are connected between the VOUT (TAB) pin and the ADJ (GND) pin of the three-terminal voltage regulator U2; the 4 outputs OUT1, OUT2, OUT3, and OUT4 of the chip correspond to PIN2, PIN9, PIN12, and PIN19 respectively, and the resistors R1, R2, R5, and R6 are directly connected in series with the output channel for output current sampling. , the channel current positive feedback and channel current negative feedback drawn from both ends are connected to the ADC of the external controller to sample the output current data; the control signal inputs corresponding to the 4 outputs are IN1, IN2, IN3, IN4, and the corresponding pins are PIN17, PIN14, PIN7, PIN4; the external controller inputs the PWM control signal by connecting to the input pin; resistors R3, R4, R7, and R8 are pull-down resistors at the signal input end, and one end of the pull-down resistor is connected to the control signal input end and the other end is grounded; the EN end, i.e. PIN16, is the enable end of the chip, i.e. high level is valid, and the chip function is activated when the external controller outputs a high level, R9 is the pull-down resistor at the EN end, connected between EN and GND, and the resistance value is the same as the four pull-down resistors of resistors R3, R4, R7, and R8; PIN1, PIN10, PIN11, PIN15, PIN20, and PIN21 are circuit grounds.

[0019] As a further technical solution, the above-mentioned output circuit includes capacitor C3, capacitor C4, capacitor C5, freewheeling diode D1 and a coil. The head end of the coil is connected to the power supply VCC, and the tail end is connected to the output channel of the control circuit. The bypass capacitor group composed of capacitor C3, capacitor C4 and capacitor C5 is connected in parallel at both ends of the power supply; the freewheeling diode D1 is connected in reverse parallel at both ends of the coil.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The product of the present invention has a large braking torque.

[0022] The present invention uses the magnetic field generated by the coil to directly act on the magnetorheological fluid. The magnetorheological fluid in the sealed cavity is magnetized and instantly changes from liquid to solid. The brake shaft is connected to the rotating disk. The rotating disk and the brake shaft 3 rotate in the same direction, thereby driving the transmission wheel of the outer ring of the rotating disk to rotate in the opposite direction. When the transmission wheel rotates, braking pressure is generated on the disk pressure block, so that all the pressure modules are reversed as a whole, and then the magnetorheological fluid inside the sealed cavity is pressurized. The solid magnetorheological fluid generates a braking torque on the brake shaft to achieve braking. Because the braking of the present invention mainly depends on electric current, the present invention can replace the traditional vacuum generating device and be used in new energy vehicles.

[0023] 2. The present invention adopts self-amplification for braking, and the product is light in weight.

[0024] The present invention has a magnetorheological fluid in the rotating disk and the rotating disk is close to the coil and the magnetic ring, which has a strong magnetization degree and magnetization effect on the magnetorheological fluid. After the magnetorheological fluid in the rotating disk is magnetized, the magnetorheological fluid inside it is in contact with the brake shaft, and the center of the rotating disk is a gear-shaped inner cavity, which is used to realize that after the magnetorheological fluid is magnetized, the rotating shaft drives the magnetorheological fluid to rotate, and the magnetorheological fluid drives the rotating disk to rotate. Then the rotation of the rotating disk will make the pressurizing module work, realize the self-amplifying braking work, and more effectively and reasonably convert the rotational torque generated when the car is running into the braking torque to stop it. There is no need to rely on parts such as armatures for pressurization. When installing, a bearing matching the brake shaft is set at the center of the left and right bottom plates, and is set on the axle of the front wheel or the rear wheel to minimize the impact on the speed of the car.

[0025] 3. The structure of the present invention is simple and effective.

[0026] The present invention adopts the mode of clamping the annular protrusion with the second annular groove to realize the fixed connection between the rotating disk and the sealing cylinder, and then cooperates with the fixing strip to be fixedly connected with the side plate of the shell to realize the suspended positioning of the sealing cylinder and the rotating disk. When the car is driving normally, the magnetorheological fluid is in a liquid state, the fixing strip is used for the sealing cylinder not to rotate, and the rotating disk is driven by the liquid magnetorheological fluid to rotate slightly. Therefore, the present invention also designs a force limiting spring, whose pulling force is greater than the force of the magnetorheological fluid driving the rotating disk to rotate, so that the rotating disk is not affected by the magnetorheological fluid, ensuring the normal driving of the car. When the car brakes, the fixing strip prevents the sealing cylinder from rotating, and then the relative rotation of the rotating disk and the sealing cylinder is realized by the mode of clamping the annular protrusion with the second annular groove, thereby realizing braking. The present invention arranges the fixing strip symmetrically on the side of the sealing cylinder to achieve the most stable positioning effect. The present invention adopts a cylinder rather than a rectangle to connect the disk pressure block and the shaft pressure block, so the structural relationship of the module for pressurizing the sealing cylinder and the rotating disk will realize a limit for the overall pressure module. The disk pressure module of the present invention is set to be L-shaped, which can not only receive the pressure of the transmission teeth through the serrations, but also limit the transmission teeth to a certain extent; the length and width of the shaft pressure block of the present invention are both larger than the diameter of the hole through which the connecting rod is inserted on the sealing cylinder, and the surface of the shaft pressure block facing the brake shaft is set to be an arc surface with the same arc as the brake shaft, so as to ensure that the increased braking force during braking can be more comprehensively and effectively applied to the magnetized magnetorheological fluid, thereby more comprehensively increasing the braking torque of the magnetorheological fluid on the brake shaft.

[0027] 4. The present invention is easy to assemble.

[0028] In order to improve the assembly efficiency of the product, the present invention divides the sealing cylinder into two symmetrical halves, which is convenient for disassembly and assembly of the pressurizing module. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the appearance structure of a self-amplifying magnetorheological fluid brake device of the present invention;

[0030] Figure 2 A schematic diagram of the internal structure of a self-amplifying magnetorheological fluid brake device of the present invention;

[0031] Figure 3 for Figure 2 Right view after omitting the right bottom plate;

[0032] Figure 4 This is a three-dimensional diagram of a self-enhancing magnetorheological fluid brake device of the present invention with the side plate and the right bottom plate omitted;

[0033] Figure 5 It is a structural schematic diagram of the magnetorheological brake unit of the present invention;

[0034] Figure 6 It is a schematic diagram of the structure of the magnetic conductive module of the present invention;

[0035] Figure 7 for Figure 6 Exploded view of the magnetic conductivity module;

[0036] Figure 8 It is a schematic diagram of the structure of the rotating disk of the present invention;

[0037] Fig. 9 for Figure 8 AA section view;

[0038] Fig.10 It is a schematic diagram of the sealing cylinder structure of the present invention;

[0039] Fig.11 This is a control principle diagram of the coil current control module of the present invention;

[0040] Fig.12 is an output circuit diagram of the present invention;

[0041] Fig.13 It is a control circuit diagram of the present invention.

[0042] Figure markings: 1-housing, 2-axle, 3-brake shaft, 4-bottom plate, 5-side plate, 6-magnetorheological brake unit, 601-magnetic conductive module, 602-rotating disk, 603-transmission gear, 604-gear-shaped inner cavity, 605-first annular groove, 606-fixing bar, 607-gear fixing rod, 608-disc pressure block, 609-connecting rod, 610-shaft pressure block, 611-spring fixing rod, 612-force limiting spring, 613-first magnetic conductive ring, 614-second magnetic conductive ring, 615-third magnetic conductive ring, 616-fourth magnetic conductive ring, 617-magnetic isolation ring, 618-coil, 619-annular protrusion, 7-sealing cylinder, 8-second annular groove, 9-external controller, 10-control circuit; a-left side, b-right side, c-front side, d-rear side. DETAILED DESCRIPTION

[0043] The present invention is further described in detail below in conjunction with examples, but the implementation mode of the present invention is not limited to the scope represented by the examples.

[0044] Embodiment 1:

[0045] like Figure 1-5As shown, a self-enhancing magnetorheological fluid brake device includes a shell 1, an axle 2 and a brake shaft 3, wherein the axle 2 is arranged in the brake shaft 3 and rotates together, the shell 1 is surrounded by left and right bottom plates 4 and side plates 5 to form a cylindrical working chamber, the axle 2 and the brake shaft 3 are arranged in the working chamber through the left and right bottom plates 4, and two groups of symmetrical magnetorheological brake units 6 and a sealing cylinder 7 are also arranged in the working chamber, the sealing cylinder 7 is centered on the brake shaft 3 and is arranged between the two groups of magnetorheological brake units 6, the magnetorheological brake unit 6 includes a magnetic conductive module 601, a rotating disk 602, a plurality of transmission gears 603 and a pressurizing module, the magnetic conductive module 601 and the rotating disk 602 are arranged in sequence from the outside to the inside with the brake shaft 3 as the center, the magnetic conductive module 601 is arranged on the brake shaft 3, the rotating disk 602 is provided with a gear-shaped inner cavity 604 in the center, and a first annular groove 605 which is engaged with the sealing cylinder 7 and can rotate relatively is provided on the outer ring of the gear-shaped inner cavity 604, The module 601, the rotating disk 602 and the sealing cylinder 7 are assembled to form a sealed cavity for containing the magnetorheological fluid; a fixing strip 606 is provided on the side of the sealing cylinder 7, and the sealing cylinder 7 is fixedly connected to the side plate 5 through the fixing strip 606, so that the sealing cylinder 7 and the rotating disk 602 are suspended and positioned; the outer ring of the rotating disk 602 is set as a gear structure, and the transmission gears 603 are evenly distributed on the outer ring of the rotating disk 602 and meshed with it, and a gear fixing rod is provided at the center of each transmission gear 603 607, the gear fixing rod 607 is fixedly connected to the corresponding bottom plate 4; the pressurizing modules are respectively arranged on the same side of the transmission gear 603, and the pressurizing module is composed of a disk pressurizing block 608, a connecting rod 609 and a shaft pressurizing block 610 connected in sequence. The disk pressurizing block 608 is arranged beside the transmission gear 603, and the disk pressurizing block 608 is provided with saw teeth meshing with the transmission gear 603. The connecting rod 609 is inserted into the sealing cavity from the side of the sealing cylinder 7 and is clamped on the sealing cylinder 7 through the shaft pressurizing block 610. A spring fixing rod 611 is respectively arranged on the rotating disk 602 and the corresponding bottom plate 4, and a force limiting spring 612 is arranged between the two spring fixing rods 611. The fixing strip 606 is centered on the sealing cylinder 7 and is symmetrically arranged on the side of the sealing cylinder 7 to achieve the most stable positioning effect. The sealing cylinder 7 is horizontally divided into two symmetrical halves, which are convenient for disassembly and assembly of the pressurizing module. The connecting rod 609 is a cylinder, and the structural relationship of the module for pressurizing the sealing cylinder 7 and the rotating disk 602 will achieve a limit for the overall pressurizing module. The disk pressurizing block 608 is L-shaped, and the transmission gear 603 is located at the bending part of the L-shape, which can not only receive the pressure of the transmission gear through the saw teeth, but also limit the transmission gear to a certain extent; the length and width of the shaft pressurizing block 610 are both larger than the diameter of the hole in the sealing cylinder 7 where the connecting rod 609 is inserted, and the surface of the shaft pressurizing block 610 facing the brake shaft 3 is set to be an arc surface with the same arc as the brake shaft 3, so as to ensure that the increased braking force during braking can be more comprehensively and effectively applied to the magnetized magnetorheological fluid, and more comprehensively increase the braking torque of the magnetorheological fluid on the brake shaft 3.The pulling force of the force-limiting spring 612 on the rotating disk is greater than the force of the magnetorheological fluid driving the rotating disk 602 to rotate in the non-magnetized state, so that the rotating disk 602 in the normal driving state is not affected by the magnetorheological fluid, and is less than the force of the magnetorheological fluid driving the rotating disk 602 to rotate in the magnetized state, so as to ensure the braking. The transmission gears 603 of each set of magnetorheological brake units 6 are set to 4, and the pressure modules are set to 4.

[0046] like Figure 6-7 As shown, the magnetic conductive module 601 includes a magnetic conductive cavity, a magnetic isolation ring 617 and a coil 618. The magnetic conductive cavity is a cylindrical cavity surrounded by a first magnetic conductive ring 613, a second magnetic conductive ring 614, a third magnetic conductive ring 615 and a fourth magnetic conductive ring 616. The first magnetic conductive ring 613 is the inner ring of the cylindrical cavity, the second magnetic conductive ring 614 is arranged on the outer side surface of the first magnetic conductive ring 613, and the third magnetic conductive ring 615 and the fourth magnetic conductive ring 616 are the left and right bottom surfaces of the cylindrical cavity; the first magnetic conductive ring 613 and the third magnetic conductive ring 615 are installed on the brake shaft 3, and the magnetic isolation ring 617 is clamped between the fourth magnetic conductive ring 616 and the first magnetic conductive ring 613.

[0047] like Figure 8-9 As shown, an annular protrusion 619 is provided on the side of the first annular groove 605, and a second annular groove 8 is provided at the connection between the sealing cylinder 7 and the rotating disk 602, which is clamped with the annular protrusion 619, thereby realizing the fixed connection between the rotating disk 602 and the sealing cylinder 7, and then the fixing strip 606 is fixedly connected with the side plate 5 of the shell 1, thereby realizing the suspended positioning of the sealing cylinder 7 and the rotating disk 602.

[0048] Embodiment 2:

[0049] like Fig.11 As shown, based on Example 1, the circuit of the present invention includes a coil current control module, the coil current control module includes an external controller 9, a control circuit 10 and an output circuit including a coil 618, the external controller 9 is electrically connected to the input end of the control circuit 10, and the output end of the control circuit 10 is electrically connected to the output circuit.

[0050] The external controller 9 can be controlled by various PLCs, microcontrollers or other controllers. The present invention takes the mature Arduino development board as an example for the controller control channel 1 to output; the development board digital signal output port 9 is used as the output port of the PWM control signal, and it is connected to the signal input port 1 of the control circuit 10 ( Fig.13 Connect the digital signal port 10 of the development board to the enable terminal of the control circuit 10 ( Fig.13The analog signal port A0 of the Arduino development board is connected to the current sampling output port of the control circuit 10, and the voltage across the sampling resistor is read through the internal ADC to obtain the current information.

[0051] like Fig.13 As shown, since the maximum current required for the magnetorheological brake to work is 3A, the control circuit 10 uses the power control chip L9349LF of STMicroelectronics as the core device, and its maximum load current is 5A, which can fully meet the control requirements of the magnetorheological brake. The working voltage of the chip is 4.5~32V, and it has 4 independently controllable output channels. By controlling the duty cycle of the input PWM signal, the load current can be easily controlled to control the brake for braking.

[0052] Fig.13 U2 in the figure is a three-terminal voltage regulator, which converts the power supply VCC into 5V to power the logic circuit of the chip. VIN, VOUT (TAB), and ADJ (GND) are its power input, 5V output, and ground pins respectively. The VIN pin is connected to the power supply VCC. VOUT (TAB) is connected to the VS pin (PIN5) of the chip to power the logic circuit in the chip. Capacitors C1 and C2 are filter capacitors for the chip's 5V logic power supply, which are connected across VOUT (TAB) and ADJ (GND) of the three-terminal voltage regulator U2. The capacities of capacitors C1 and C2 are 100uf and 0.1uf respectively.

[0053] The chip's 4 outputs OUT1 (5A), OUT2 (5A), OUT3 (3A), and OUT4 (3A) correspond to PIN2, PIN9, PIN12, and PIN19, respectively. The resistors R1, R2, R5, and R6 are directly connected in series with the output channels as output current sampling resistors with a resistance of 0.1 ohms. The positive feedback of the channel (channel number) current and the positive feedback of the channel (channel number) current are connected to the ADC of the external controller 9 to sample the output current data, corresponding to a range of 100mv / 1A. The control signal inputs corresponding to the 4 outputs are IN1, IN2, IN3, and IN4, respectively, and the corresponding pins are PIN17, PIN14, PIN7, and PIN4. The external controller 9 inputs the PWM control signal by connecting to the input pins, and controls the current of the output channel by changing the duty cycle of the PWM signal. The larger the signal duty cycle, the larger the output current. Resistors R3, R4, R7 and R8 are pull-down resistors at the signal input end, with a resistance of 10 kilo-ohms. One end of the pull-down resistor is connected to the control signal input end and the other end is grounded. The function is to prevent the chip from being turned on by mistake when there is no signal input and encountering interference. The EN end (PIN16) is the enable end of the chip (high level is valid), which determines whether the chip is activated and used. When the external controller 9 outputs a high level, the chip function is activated. Resistor R9 is the pull-down resistor at the EN end, and is connected between EN and GND. The resistance is the same as the other four pull-down resistors, which is used to ensure that the chip will not be turned on by mistake when there is no signal input. PIN1, PIN10, PIN11, PIN15, PIN20 and PIN21 are circuit grounds.

[0054] Table 1 is the pin function table of the chip and the three-terminal regulator U2

[0055]

[0056]

[0057] like Fig.12 As shown, the head end of coil 618 is connected to the power supply VCC, and the tail end is connected to the circuit output channel. In the figure, a bypass capacitor group consisting of three 10uf capacitors C3, C4 and C5 is connected in parallel at both ends of the power supply to improve the transient response capability of the brake. The freewheeling diode D1 is reversely connected in parallel at both ends of the magnetorheological brake coil 618 to prevent the induced electromotive force from breaking through the circuit when switching quickly from the braking state to the non-braking state, causing circuit damage and improving safety and stability.

[0058] When the car is running normally, the magnetorheological fluid is in liquid state, the fixing strip 606 is used to prevent the sealing cylinder 7 from rotating, and the rotating disk 602 is driven by the liquid magnetorheological fluid to rotate slightly. Therefore, the present invention also designs a force-limiting spring 612, whose pulling force is greater than the force of the magnetorheological fluid driving the rotating disk 602 to rotate, so that the rotating disk 602 is not affected by the magnetorheological fluid, ensuring the normal driving of the car. When the car brakes, the fixing strip 606 prevents the sealing cylinder 7 from rotating, and then the relative rotation of the rotating disk 602 and the sealing cylinder 7 is achieved by the way of the annular protrusion 619 and the second annular groove 8, thereby achieving braking.

[0059] The present invention converts the rotation torque generated when the vehicle is running into a braking torque for stopping the vehicle, and the method is as follows:

[0060] The present invention is installed on the front wheel axle 2 of the new energy vehicle, and bearings are installed at the center of the left and right bottom plates 4 to ensure the rotation connection with the brake shaft 3. During normal driving, the magnetorheological fluid is in liquid state, the axle 2 rotates, and the force-limiting spring 612 pulls the rotating disk 602 so that it is not driven by the brake shaft 3; during braking, the coil 618 is energized to generate a magnetic field, so that the magnetorheological fluid instantly changes from liquid to solid state, the brake shaft 3 is connected to the rotating disk 602, and the rotating disk 602 and the brake shaft 3 rotate in the same direction, thereby driving the driving wheel of the outer ring of the rotating disk 602 to rotate in the opposite direction. When the driving wheel rotates, the disk pressure block 608 generates braking pressure, so that all the pressure modules are reversed as a whole, and then the magnetorheological fluid inside the sealed cavity is pressurized, and the solid magnetorheological fluid generates a braking torque on the brake shaft 3 to achieve braking.

[0061] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "head", "tail", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present invention. It should also be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection; it can be a detachable connection; it can also be a point connection; it can be a direct connection; it can be an indirect connection through an intermediate medium, so that the internals of the two elements can be connected. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The device connection methods not fully described in the present invention are all understood as conventional connection methods in the field.

[0062] The above embodiments are only specific examples for further describing the purpose, technical solutions and beneficial effects of the present invention, and the present invention is not limited thereto. Any modification, equivalent replacement, improvement, etc. made within the scope disclosed by the present invention are included in the protection scope of the present invention.

Claims

1. A self-enhancing magnetorheological fluid brake device, comprising a housing, an axle and a brake shaft, wherein the axle is arranged in the brake shaft and rotates together, the housing is surrounded by left and right bottom plates and side plates to form a cylindrical working chamber, the axle and the brake shaft pass through the left and right bottom plates and are arranged in the working chamber, characterized in that: The working chamber is also provided with two groups of symmetrical magnetorheological brake units and a sealing cylinder. The sealing cylinder is centered on the brake shaft and is arranged between the two groups of magnetorheological brake units. The magnetorheological brake unit includes a magnetic conductive module, a rotating disk, a plurality of transmission gears and a pressurizing module. The magnetic conductive module and the rotating disk are arranged in sequence from the outside to the inside with the brake shaft as the center. The magnetic conductive module is arranged on the brake shaft. The center of the rotating disk is provided with a gear-shaped inner cavity. The outer ring of the gear-shaped inner cavity is provided with a first annular groove that is clamped with the sealing cylinder and can rotate relatively. The magnetic conductive module, the rotating disk and the sealing cylinder are assembled to form a sealed cavity for containing magnetorheological fluid. A fixing strip is provided on the side of the sealing cylinder, and the sealing cylinder is fixedly connected to the side plate through the fixing strip, so that the sealing cylinder and the rotating disk are suspended in position. The outer ring is set as a gear structure, and the transmission gears are evenly distributed on the outer ring of the rotating disk and meshed with it. A gear fixing rod is provided in the center of each transmission gear, and the gear fixing rod is fixedly connected to the corresponding bottom plate; the pressurizing modules are respectively arranged on the same side of the transmission gears, and the pressurizing module is composed of a disk pressurizing block, a connecting rod and a shaft pressurizing block connected in sequence, the disk pressurizing block is arranged next to the transmission gear, and the disk pressurizing block is provided with serrations meshing with the transmission gear, and the connecting rod is inserted into the sealing cavity from the side of the sealing cylinder, and is clamped on the sealing cylinder through the shaft pressurizing block; a spring fixing rod is respectively provided on the rotating disk and the corresponding bottom plate, and a force limiting spring is provided between the two spring fixing rods; an annular protrusion is provided on the side of the first annular groove, and a second annular groove clamped with the annular protrusion is provided at the connection between the sealing cylinder and the rotating disk.

2. A self-amplifying magnetorheological fluid brake device according to claim 1, characterized in that: The magnetic conductive module includes a magnetic conductive cavity, a magnetic isolation ring and a coil. The magnetic conductive cavity is a cylindrical cavity surrounded by a first magnetic conductive ring, a second magnetic conductive ring, a third magnetic conductive ring and a fourth magnetic conductive ring. The first magnetic conductive ring is an inner ring of the cylindrical cavity, the second magnetic conductive ring is arranged on the outer side surface of the first magnetic conductive ring, and the third magnetic conductive ring and the fourth magnetic conductive ring are the left and right bottom surfaces of the cylindrical cavity; the first magnetic conductive ring and the third magnetic conductive ring are installed on the brake shaft, and the magnetic isolation ring is clamped between the fourth magnetic conductive ring and the first magnetic conductive ring.

3. A self-enhancing magnetorheological fluid brake device according to claim 1, characterized in that: The fixing strip is centered on the sealing cylinder and is symmetrically arranged on the side surface of the sealing cylinder.

4. The self-amplifying magnetorheological fluid brake device according to claim 1, characterized in that: The sealing cylinder is horizontally divided into two symmetrical halves.

5. The self-amplifying magnetorheological fluid brake device according to claim 1, characterized in that: The connecting rod is a cylinder.

6. A self-enhancing magnetorheological fluid brake device according to claim 5, characterized in that: The disc pressure block is L-shaped, and the transmission gear is located at the bend of the L; the length and width of the shaft pressure block are both larger than the diameter of the hole through which the connecting rod is inserted on the sealing cylinder, and the surface of the shaft pressure block facing the brake shaft is set to an arc surface with the same arc as the brake shaft.

7. The self-amplifying magnetorheological fluid brake device according to claim 1, characterized in that: The pulling force of the force-limiting spring on the rotating disk is greater than the force of the magnetorheological fluid driving the rotating disk to rotate in the non-magnetized state, and is less than the force of the magnetorheological fluid driving the rotating disk to rotate in the magnetized state.

8. The self-amplifying magnetorheological fluid brake device according to claim 1, characterized in that: The number of transmission gears of each set of magnetorheological brake units is set to 4, and the number of pressurizing modules is set to 4.

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