Integrated electronic hydraulic brake booster unit with planetary gear speed reducing mechanism
Technical Field
The utility model relates to an automobile parts technical field specifically relates to an integrated form electron hydraulic braking booster unit with planetary gear reduction gears.
Background
With the continuous development and progress of the automobile industry technology, more and more automobiles develop towards electric, intelligent and clean. Most of the existing new energy automobiles adopt batteries, natural gas, batteries and gasoline or diesel oil to provide power for the new energy automobiles. Taking a pure electric vehicle as an example, the vehicle is driven by a motor, and a traditional engine is not used for providing a power source for a vacuum booster installed on the vehicle. Although, the electronic vacuum pump in the prior art can provide a vacuum source for the electric vehicle. However, such an electronic vacuum pump cannot achieve regenerative braking, cannot provide precise control of braking force, and also cannot meet the braking demand of intelligent driving. Accordingly, electronic hydraulic brake boosters have evolved and are continually being developed to accommodate more complex driving scenarios. However, the integration level of the electronic hydraulic brake power assisting system in the prior art is low, and the problems of operation vibration and noise are not solved effectively.
For example, chinese patent No. ZL201310061203.7 discloses an electronic hydraulic brake device, including: a pedal cylinder portion that generates hydraulic pressure by pressurization of a pedal; a main cylinder part sensing the pedal and generating hydraulic pressure; wheel cylinder portions that are attached to a plurality of wheels, respectively, and that provide braking force to the wheels; a storage portion that stores a fluid; a mixing circuit part which connects the pedal cylinder part and a part of the wheel cylinder part, guides fluid, and communicates with the storage part and the main cylinder part; a main circuit part which connects the main cylinder part and the wheel cylinder part which is not connected with the mixing circuit part, guides the fluid and is communicated with the storage part; and a hydraulic pressure separating part which connects the mixing circuit part and the main circuit part and limits the movement of the fluid; the invention simplifies the hydraulic circuit and reduces the number of accessories. However, the brake device is low in integration level, large in size, difficult to arrange in a front cavity of an automobile, low in universality and inconvenient to install.
For another example, the chinese patent application with application number 201610963083.3 discloses a brake booster, which includes an input rod that is driven by a brake pedal and moves forward along an axial direction and a boosting push element that converts the rotary driving motion of a motor into a linear motion, a relative displacement detection device for measuring the relative stroke of the input rod and the boosting push element is disposed between the input rod and the boosting push element, the relative displacement detection device includes a first displacement sensor, a first magnet and a connecting wire, the first displacement sensor and the first magnet are disposed opposite to each other and induce each other, the first displacement sensor is connected with the boosting push element, and the first magnet is connected with the input rod. According to the invention, the relative displacement detection device is arranged between the input rod and the power-assisted pushing piece, and the relative displacement detection device can be used for detecting the relative displacement of the input rod and the power-assisted pushing piece in the braking process, so that the ECU controls the motor to drive the power-assisted pushing piece to move, and the accuracy is improved. However, the response speed is slow, and the structure is not compact enough.
In addition, the electronic hydraulic booster in the prior art has lower transmission efficiency, lower accuracy and higher noise.
Disclosure of Invention
For overcoming the defect and not enough among the above-mentioned prior art, the utility model provides an integrated form electronic hydraulic braking booster unit with planetary gear reduction gears that integrated level is higher, transmission efficiency is higher, the accuracy is higher, the noise is less and shock resistance is stronger. In addition, the device not only can satisfy the demand of electric motor car, but also can satisfy the demand in the aspect of the braking of intelligent driving.
In order to achieve the above object, the first technical solution of the present invention is: the integrated electronic hydraulic brake booster device with the planetary gear speed reducing mechanism comprises a brake main cylinder component, a shell component, a motor and a controller; the inner cavity of the brake master cylinder assembly is communicated with the cavity of the shell assembly; a spring assembly is mounted in the inner cavity; the brake master cylinder is characterized in that a first flange protruding axially is arranged on the end face of the top of the brake master cylinder, a slide block return spring is sleeved on the first flange, one end of the slide block return spring is sleeved on the first flange, and the other end of the slide block return spring is sleeved on a second flange of the input slide block; the motor is provided with a hollow output shaft, a ball screw of a ball screw pair is arranged in the hollow output shaft, and a screw nut of the ball screw pair is rotatably arranged in the cavity through a rolling bearing; and a planetary gear speed reducing mechanism is fixedly arranged on the hollow output shaft.
The brake master cylinder assembly mainly comprises a brake master cylinder, a first spring assembly, a second spring assembly, a first piston, a second piston and a connecting sleeve. A first spring assembly, a first piston, a second spring assembly and a second piston are sequentially arranged in the inner cavity of the brake master cylinder from left to right. The connecting sleeve is arranged at the upper part of the brake main cylinder.
The shell assembly mainly comprises a shell, a planetary gear speed reducing mechanism, a ball screw pair, a bearing, an input sliding block, an output rod head, an output rod connecting shaft, an output rod seat, a feedback disc, an input shaft limiting metal plate, a Hall displacement sensor chip and a magnetic material. The output rod head, the output rod connecting shaft, the output rod seat, the feedback disc and the input sliding block are sequentially installed to form an assembly, the assembly slides in the cavity of the shell body together from left to right, and the ball screw pair comprises a screw nut and a ball screw.
Preferably, the planetary gear speed reducing mechanism comprises a planet carrier, a sun gear, a planet gear shaft, a planet gear and an outer gear ring; the planetary gear is fixedly arranged on the planetary gear shaft through a fixed bearing and is limited by a shaft retainer ring; and the planet wheel shaft is fixedly arranged on the planet carrier.
In any of the above schemes, preferably, the device further comprises a pedal input shaft, wherein the pedal input shaft sequentially penetrates through the hollow output shaft of the motor and the input shaft limiting metal plate to be in movable contact with the input sliding block; the pedal input shaft is movably arranged in the ball screw of the hollow output shaft.
In any of the above aspects, preferably, the carrier of the planetary gear reduction mechanism is fixedly attached to the screw nut through a flat key.
In any of the above aspects, preferably, the planet gear is engaged with an outer ring gear, and the outer ring gear is fixedly mounted at the top position of the cavity.
In any of the above aspects, it is preferred that the spring assembly comprises a first spring assembly and a second spring assembly; and a first piston is arranged at the top of the first spring assembly, and a second piston is arranged at the top of the second spring assembly.
In any of the above schemes, preferably, the input slider is fixedly provided with a hall displacement sensor chip through a fixing bracket; the Hall displacement sensor chip is electrically connected with the controller through a circuit; the Hall displacement sensor chip can move left and right along with the input sliding block.
In any of the above schemes, preferably, the input shaft limiting metal plate is provided with a magnetic material.
In any of the above aspects, preferably, the magnetic material is a magnet.
In any of the above schemes, preferably, a feedback disk is fixedly mounted on the input slider, and the feedback disk is disposed in a mounting groove formed in an axial position of the input slider.
In any of the above schemes, preferably, an axial circular groove is further formed in the axial direction of the input slider; a force output rod seat is buckled in the axial circular groove; the output rod connecting shaft is fixedly arranged at the axis position of the output rod seat; one end of the output rod connecting shaft is arranged in the central hole of the output rod seat, and the other end of the output rod connecting shaft is fixedly connected with an output rod head; the output rod head is movably contacted with the concave part of the second piston.
In any of the above embodiments, preferably, an input shaft guide sleeve is fitted over the tail portion of the pedal input shaft, and a push rod spring is fitted over the input shaft guide sleeve.
In any of the above schemes, preferably, an axial mounting hole is formed in the end face of the tail part of the pedal input shaft, and a ball head push rod is riveted in the axial mounting hole.
In any of the above schemes, preferably, a push rod spring seat is rotatably sleeved on the ball head push rod; one end of the push rod spring is sleeved on the input shaft guide sleeve, and the other end of the push rod spring is sleeved on the push rod spring seat.
In any of the above schemes, preferably, the tail part of the ball head push rod is fixedly provided with a push rod fork through a locking nut.
In any of the above embodiments, preferably, a dust cover is fitted around the outer circumference of the pusher spring.
In any of the above schemes, preferably, at least one connecting sleeve is fixedly installed on the brake master cylinder in a penetrating manner, and an oil inlet joint is fixedly installed on the connecting sleeve and is communicated with an inner cavity of the brake master cylinder.
In any of the above solutions, preferably, the number of the connecting sleeves is two, and the connecting sleeves are fixedly installed on the master cylinder at intervals.
In any of the above solutions, it is preferable that the master cylinder is fixedly installed at the bottom of the housing through a seal bushing.
In any of the above aspects, preferably, the motor is a dc brushless motor.
In any of the above aspects, it is preferable that the number of the planetary gears is three.
A second object of the present invention is to provide an electronic hydraulic brake boosting method, which comprises the following steps:
step S1, a driver steps on a brake pedal to drive the pedal input shaft to move left and drive the magnet to move left, and the Hall displacement sensor chip and the magnet generate relative displacement;
step S2, the Hall displacement sensor chip sends the measured signal to a controller, and the controller controls the motor to start and run;
step S3, a hollow output shaft of a motor rotates to drive a planetary reduction gear mechanism to be linked with a screw nut, and then a ball screw is driven to move leftwards;
step S4, the ball screw moves leftwards and pushes the input slide block contacted with the ball screw to move leftwards; finally, the output rod head pushes the second piston to move leftwards and compresses the inner cavity of the brake main cylinder to establish hydraulic pressure to realize braking;
sequentially executing the steps S1-S4;
step S5, when the driver releases the brake pedal to release the brake, the spring force of the push rod spring makes the magnet move rightwards together with the pedal input shaft, the Hall displacement sensor chip sends the measured signal to the controller, the controller controls the motor to rotate reversely, and the ball screw moves rightwards; the input sliding block is rightwards restored to the initial position under the combined action of the sliding block return spring, the first spring assembly and the second spring assembly;
and step S6, when the motor fails in emergency, a driver steps on a brake pedal, and the brake pedal pushes a second piston to compress an inner cavity of a brake master cylinder to establish hydraulic pressure to realize braking through a push rod fork, a ball head push rod, a pedal input shaft, a feedback disc, a force rod seat, a force rod connecting shaft and a force rod head in sequence.
Compared with the prior art, the utility model has the advantages of: the integrated electronic hydraulic brake power assisting device with the planetary gear speed reducing mechanism of the utility model can meet the intelligent driving brake requirement without an electronic vacuum pump; the device has the advantages of stable operation, strong impact resistance, low starting current, high reliability, small volume and convenient arrangement; the motor is adopted for driving, the response speed is high, the response time is about 120 milliseconds to 150 milliseconds, and the response time is 200 to 300 milliseconds shorter than that of an ESP module; a parameter self-adaptive fuzzy PID control strategy is designed by adopting a direct current brushless motor, and the defect that the traditional motor parameters and the parameters of a dragging load can change in the operation process, so that a PID controller with fixed parameters can not enable a system to keep the performance index during design under various working conditions is overcome. In addition, the integrated electronic hydraulic brake power assisting device with the planetary gear speed reducing mechanism is high in transmission efficiency, high in accuracy and low in noise.
Drawings
Fig. 1 is a schematic structural view of a preferred embodiment of an integrated electronic hydraulic brake booster with a planetary gear reduction mechanism according to the present invention.
Fig. 2 is a schematic structural view of a preferred embodiment of a master cylinder of an integrated electronic hydraulic brake booster with a planetary gear reduction mechanism according to the present invention.
Fig. 3 is a schematic diagram of a preferred embodiment of a spring assembly of an integrated electronic hydraulic brake booster with a planetary gear reduction mechanism according to the present invention.
Fig. 4 is a schematic structural diagram of a preferred embodiment of a lead screw nut of the integrated electronic hydraulic brake servo unit with a planetary gear reduction mechanism according to the present invention.
Detailed Description
The preferred embodiments of the present invention will be further explained with reference to the accompanying drawings;
in the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, whereby a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specified.
In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.
Example 1:
as shown in fig. 1 to 4, an integrated electronic hydraulic brake booster with a planetary gear reduction mechanism includes a pedal input shaft 24, a master cylinder 3, a housing 10, a motor 25, and a controller. The controller is installed in the plastic shell. And a PCB is arranged on the plastic shell. The plastic shell is fixedly mounted on the sheet metal bracket 34 through screws. The sheet metal bracket 34 is fixedly mounted on the housing 10 by screws. The motor 25 is a dc brushless motor. The motor 25 has a hollow output shaft 42 of hollow construction. The interior 38 of the master cylinder 3 is connected to the cavity 39 of the housing 10. Specifically, the master cylinder 3 is fixedly clamped to the bottom of the housing 10 through a seal bushing 55. A sealing retainer ring 56 is fixedly sleeved on the circumferential outer wall of the sealing shaft sleeve 55. At least one connecting sleeve 1 is fixedly arranged on the master cylinder 3 in a penetrating manner, an oil inlet joint 2 is fixedly arranged on the connecting sleeve 1, and the oil inlet joint 2 is communicated with an inner cavity 38 of the master cylinder 3. In this embodiment, the connecting sleeves 1 are two in number and are fixedly mounted on the master cylinder 3 at intervals.
A first spring assembly 35 and a second spring assembly 37 are mounted in series in the internal cavity 38. The first spring assembly 35 and the second spring assembly 37 are axially horizontally arranged. A first piston 33 is disposed on top of the first spring assembly 35. A second piston 36 is disposed on top of the second spring assembly 37. The first spring assembly 35 includes a first return spring 47, a first spring seat 48, a first stem 49, and a first top plate 50. The first spring seat 48 is of cylindrical configuration. The first valve stem 49 has a cylindrical rod-like structure. A cylindrical boss 55 is fixedly arranged at the center of the bottom of the inner cavity 38. Likewise, the cylindrical boss 55 is axially disposed. The first return spring 47 is fitted over the first spring seat 48. The first spring retainer 48 is axially snap-fitted to the cylindrical boss 55. The first valve rod 49 is disposed in the first spring seat 48 and fixedly connected to the first top plate 50 through a top through hole of the first spring seat 48. The first top plate 50 has a circular structure and the first top plate 50 is disposed in the limiting recess 57 of the first piston 33. The limiting groove 57 is a cylindrical groove with a trapezoidal structure. Further, one end of the first return spring 47 is fastened to the first spring seat 48, and the other end is fixedly connected to the first top plate 50 and is fixed and limited by the first top plate 50. A first projection 69 projecting radially is provided on the bottom circumferential wall surface of the first stem 49. The first stem 49 restrains the first stem 49 within the first spring seat 48 by the first projection 69.
The second spring assembly 37 includes a second return spring 51, a second spring seat 52, a second stem 53, and a second top plate 54. A second spring assembly 37 is disposed in the receiving chamber formed between the first piston 33 and the second piston 36. The second return spring 51 is fitted over the second spring seat 52. The second valve rod 53 passes through the top opening of the second spring seat 52 and is fixedly connected with the second top plate 54 and is fixedly limited by the second top plate 54. The second top plate 54 is movably disposed in a circular recess 58 in the bottom of the second piston 36. The circular recess 58 is likewise a cylindrical recess of trapezoidal configuration. The second valve stem 53 is provided on the bottom circumferential wall surface thereof with a second projection 70 projecting radially. The second valve stem 53 restrains the second valve stem 53 within the second spring seat 52 by the second protrusion 70.
A plurality of circular grooves, namely a first circular groove 59, a second circular groove 60, a third circular groove 61 and a fourth circular groove 62, are formed on the circumferential wall surface of the inner cavity 38 at intervals. A first seal ring 63 is embedded in the first annular groove 59, and a second seal ring 64 is embedded in the second annular groove 60. The first and second seal rings 63, 64 may be fitted around the first piston 33 and movably contact with the circumferential outer wall of the first piston 33. A third seal ring 65 is embedded in the third annular groove 61, and a fourth seal ring 66 is embedded in the fourth annular groove 62. Third seal ring 65 and fourth seal ring 66 may be fitted around second piston 36 and may be in movable contact with the circumferential outer wall of second piston 36. In the present embodiment, the first seal ring 63, the second seal ring 64, the third seal ring 65, and the fourth seal ring 66 are lip-shaped seal rings.
A first flange 40 projecting axially is provided on the top end face of the master cylinder 3. The first flange 40 is fitted with a slider return spring 5. One end of the slider return spring 5 is fitted over the first flange 40, and the other end is fitted over the second flange 41 of the input slider 29. The second piston 36 is located within the slider return spring 5. The Hall displacement sensor chip 6 is fixedly arranged on the input sliding block 29 through a fixed bracket; the Hall displacement sensor chip 6 is electrically connected with the controller through a circuit. The Hall displacement sensor chip 6 can move left and right along with the input slide block 29. The magnetic material 7 is mounted on the input shaft stopper metal plate 28. In this embodiment, the magnetic material 7 is a magnet.
The pedal input shaft 24 sequentially passes through the hollow output shaft 42 of the motor 25 and the input shaft limiting metal plate 28 to be in movable contact with the input sliding block 29. A hollow ball screw is rotatably fitted over the pedal input shaft 24, and a screw nut 43 of the ball screw is rotatably fixed in the cavity 39 by a bearing 8. In the present embodiment, the lead screw nut 43 is fixedly connected to the carrier 26 of the planetary gear reduction mechanism. Specifically, the planet carrier 26 of the planetary gear reduction mechanism is fixedly sleeved on the second step circle 71 of the screw nut 43 through the flat key 9. The bearing 8 is fitted over the first step circle 68 of the spindle nut 43.
A planetary gear reduction mechanism is fixedly mounted on the hollow output shaft 42 of the motor 25. The planetary gear speed reducing mechanism comprises a planet carrier 26, a sun gear 16, a planet gear shaft 11, a planet gear 12 and an outer gear ring 13; the planetary gear 12 is fixedly arranged on the planetary gear shaft 11 through a fixed bearing 14 and limited by a shaft retainer ring 15; the planetary gear shaft 11 is fixedly mounted on the carrier 26. The planet gears 12 are meshed with an outer gear ring 13, and the outer gear ring 13 is fixedly installed at the top position of the cavity 39 through interference fit. The sun gear 16 is fixedly sleeved on the hollow output shaft 42 through interference fit. In the present embodiment, the number of the planetary gears 12 of the planetary gear speed reduction mechanism is three.
Rotation of the hollow output shaft 42 rotates the sun gear 16. The rotation of the sun gear 16 rotates the planet gears 12 engaged with it and fixed to the planet carrier 36, which in turn rotates the planet carrier 26. The carrier 26 is interlocked with a screw nut 43 of the ball screw via a flat key 9. The rotation of the planet carrier 26 drives the screw nut 43 to rotate, so as to drive the ball screw 27 to move left and right, so as to drive the input slider 29 to move left, and finally the output rod head 4 pushes the second piston 36 to compress the brake master cylinder 3 left to establish hydraulic pressure, so as to realize the brake function.
A feedback disk 30 is fixedly mounted on the input slider 29. The feedback disk 30 is disposed in a mounting groove 44 formed in the axial position of the input slider 29. Further, a mounting groove 44 having a circular structure is formed at a center position of a left side of the input slider 29. A feedback disk 30 of circular configuration is removably mounted in the mounting slot 44. An axial circular groove 45 is further formed in the axial direction of the input slider 29. The axial circular groove 45 is internally buckled with the force rod seat 31. A feedback disc 30 is interposed between the input slider 29 and the output lever seat 31. The output rod socket 31 is on the left side of the input slider 29. An output rod connecting shaft 32 is fixedly riveted at the left axial center position of the output rod seat 31; one end of the output rod connecting shaft 32 is riveted with the output rod seat 31 and is positioned in the central hole of the output rod seat 31, and the other end is fixedly connected with the output rod head 4. The force tip 4 is in moving contact with the recess 67 of the second piston 36.
An input shaft guide sleeve 17 is sleeved on the tail part of the pedal input shaft 24. A push rod spring 18 is fitted over the input shaft guide sleeve 17. An axial mounting hole 46 is formed in the rear end surface of the pedal input shaft 24. A ball plunger 22 is riveted into the axial mounting hole 46. A push rod spring seat 20 is rotatably fitted over the ball push rod 22. One end of the push rod spring 18 is sleeved on the input shaft guide sleeve 17, and the other end is sleeved on the push rod spring seat 20. A dust cover 19 is fitted around the outer circumference of the pusher spring 18. The tail part of the ball head push rod 22 is fixedly provided with a push rod fork 21 through a locking nut 23. The push rod fork 21 is connected to a brake pedal of the vehicle.
The boosting operation of the integrated electronic hydraulic brake booster with the planetary gear speed reduction mechanism in the embodiment includes the steps of:
step S1, the driver steps on the brake pedal to drive the pedal input shaft 24 to move leftwards and drive the magnet to move leftwards, and the Hall displacement sensor chip 6 and the magnet generate relative displacement;
step S2, the Hall displacement sensor chip 6 sends the measured signal to a controller, and the controller controls the motor 25 to start to run;
step S3, the hollow output shaft 42 of the motor 25 rotates to drive the planetary reduction gear mechanism and the screw nut 43 to link, and then the ball screw 27 is driven to move leftwards;
step S4, the ball screw 27 moves leftwards and pushes the input slide block 29 contacted with the ball screw to move leftwards; finally, the output rod head 4 pushes the second piston 36 to move leftwards and compress the inner cavity 38 of the brake master cylinder 3 to establish hydraulic pressure to realize braking;
sequentially executing the steps S1-S4;
step S5, when the driver releases the brake pedal to release the brake, the spring force of the push rod spring 18 makes the magnet move rightwards together with the pedal input shaft 24, the Hall displacement sensor chip 6 sends the measured signal to the controller, the controller controls the motor 25 to rotate reversely, and the ball screw 27 moves rightwards; the input slider 29 is restored to the original position rightward by the cooperation of the slider return spring 5 and the first and second spring assemblies 35 and 37;
step S6, when the motor 25 fails in emergency, the driver steps on the brake pedal, and the brake pedal sequentially passes through the push rod fork 21, the ball head push rod 22, the pedal input shaft 24, the feedback disc 30, the output rod seat 31, the output rod connecting shaft 32 and the output rod head 4 to push the second piston 36 to compress the inner cavity 38 of the brake master cylinder 3 to establish hydraulic pressure to realize braking.
Example 2:
as shown in fig. 1 to 4, an integrated electronic hydraulic brake assist device without a planetary gear reduction mechanism includes a pedal input shaft 24, a master cylinder 3, a housing 10, a motor 25, and a controller. The controller is installed in the plastic shell. And a PCB is arranged on the plastic shell. The plastic shell is fixedly mounted on the sheet metal bracket 34 through screws. The sheet metal bracket 34 is fixedly mounted on the housing 10 by screws. The motor 25 is a dc brushless motor or a stepping motor. The motor 25 has a hollow output shaft 42 of hollow construction. The interior 38 of the master cylinder 3 is connected to the cavity 39 of the housing 10. Specifically, the master cylinder 3 is fixedly clamped to the bottom of the housing 10 through a seal bushing 55. A sealing retainer ring 56 is fixedly sleeved on the circumferential outer wall of the sealing shaft sleeve 55. At least one connecting sleeve 1 is fixedly arranged on the master cylinder 3 in a penetrating manner, an oil inlet joint 2 is fixedly arranged on the connecting sleeve 1, and the oil inlet joint 2 is communicated with an inner cavity 38 of the master cylinder 3. In this embodiment, the connecting sleeves 1 are two in number and are fixedly mounted on the master cylinder 3 at intervals.
A first spring assembly 35 and a second spring assembly 37 are mounted in series in the internal cavity 38. The first spring assembly 35 and the second spring assembly 37 are axially horizontally arranged. A first piston 33 is disposed on top of the first spring assembly 35. A second piston 36 is disposed on top of the second spring assembly 37. The first spring assembly 35 includes a first return spring 47, a first spring seat 48, a first stem 49, and a first top plate 50. The first spring seat 48 is of cylindrical configuration. The first valve stem 49 has a cylindrical rod-like structure. A cylindrical boss 55 is fixedly arranged at the center of the bottom of the inner cavity 38. Likewise, the cylindrical boss 55 is axially disposed. The first return spring 47 is fitted over the first spring seat 48. The first spring retainer 48 is axially snap-fitted to the cylindrical boss 55. The first valve rod 49 is disposed in the first spring seat 48 and fixedly connected to the first top plate 50 through a top through hole of the first spring seat 48. The first top plate 50 has a circular structure and the first top plate 50 is disposed in the limiting recess 57 of the first piston 33. The limiting groove 57 is a cylindrical groove with a trapezoidal structure. Further, one end of the first return spring 47 is fastened to the first spring seat 48, and the other end is fixedly connected to the first top plate 50 and is fixed and limited by the first top plate 50. A first projection 69 projecting radially is provided on the bottom circumferential wall surface of the first stem 49. The first stem 49 restrains the first stem 49 within the first spring seat 48 by the first projection 69.
The second spring assembly 37 includes a second return spring 51, a second spring seat 52, a second stem 53, and a second top plate 54. A second spring assembly 37 is disposed in the receiving chamber formed between the first piston 33 and the second piston 36. The second return spring 51 is fitted over the second spring seat 52. The second valve rod 53 passes through the top opening of the second spring seat 52 and is fixedly connected with the second top plate 54 and is fixedly limited by the second top plate 54. The second top plate 54 is movably disposed in a circular recess 58 in the bottom of the second piston 36. The circular recess 58 is likewise a cylindrical recess of trapezoidal configuration. The second valve stem 53 is provided on the bottom circumferential wall surface thereof with a second projection 70 projecting radially. The second valve stem 53 restrains the second valve stem 53 within the second spring seat 52 by the second protrusion 70.
A plurality of circular grooves are formed on the circumferential wall surface of the inner cavity 38 at intervals, namely a first circular groove 59, a second circular groove 60, a third circular groove 61 and a fourth circular groove 62. A first seal ring 63 is embedded in the first annular groove 59, and a second seal ring 64 is embedded in the second annular groove 60. The first and second seal rings 63, 64 may be fitted around the first piston 33 and movably contact with the circumferential outer wall of the first piston 33. A third seal ring 65 is embedded in the third annular groove 61, and a fourth seal ring 66 is embedded in the fourth annular groove 62. Third seal ring 65 and fourth seal ring 66 may be fitted around second piston 36 and may be in movable contact with the circumferential outer wall of second piston 36. In the present embodiment, the first seal ring 63, the second seal ring 64, the third seal ring 65, and the fourth seal ring 66 are lip-shaped seal rings.
A first flange 40 projecting axially is provided on the top end face of the master cylinder 3. The first flange 40 is fitted with a slider return spring 5. One end of the slider return spring 5 is fitted over the first flange 40, and the other end is fitted over the second flange 41 of the input slider 29. The second piston 36 is located within the slider return spring 5. The Hall displacement sensor chip 6 is fixedly arranged on the input sliding block 29 through a fixed bracket; the Hall displacement sensor chip 6 is electrically connected with the controller through a circuit. The Hall displacement sensor chip 6 can move left and right along with the input slide block 29. The magnetic material 7 is mounted on the input shaft stopper metal plate 28. In this embodiment, the magnetic material 7 is a magnet.
The pedal input shaft 24 sequentially passes through the hollow output shaft 42 of the motor 25 and the input shaft limiting metal plate 28 to be in movable contact with the input sliding block 29. A hollow ball screw is rotatably fitted over the pedal input shaft 24, and a screw nut 43 of the ball screw is rotatably fixed in the cavity 39 by a bearing 8. In the present exemplary embodiment, the spindle nut 43 is directly fixedly connected to the hollow output shaft 42. The bearing 8 is fitted over the first step circle 68 of the spindle nut 43. The rotation of the hollow output shaft 42 drives the screw nut 43 to rotate and then drives the ball screw 27 to reciprocate, so as to drive the input slide block 29 to move left and right. The ball screw 27 is movably contacted with the input slider 29 and presses the second piston 36 to move leftward by the input slider 29. In the present embodiment, a feedback disk 30 is fixedly mounted on the input slider 29. The feedback disk 30 is disposed in a mounting groove 44 formed in the axial position of the input slider 29. Further, a mounting groove 44 having a circular structure is formed at a center position of a left side of the input slider 29. A feedback disk 30 of circular configuration is removably mounted in the mounting slot 44. An axial circular groove 45 is further formed in the axial direction of the input slider 29. The axial circular groove 45 is internally buckled with the force rod seat 31. A feedback disc 30 is interposed between the input slider 29 and the output lever seat 31. The output rod socket 31 is on the left side of the input slider 29. An output rod connecting shaft 32 is fixedly riveted at the left axial center position of the output rod seat 31; one end of the output rod connecting shaft 32 is riveted with the output rod seat 31 and is positioned in the central hole of the output rod seat 31, and the other end is fixedly connected with the output rod head 4. The force tip 4 is in moving contact with the recess 67 of the second piston 36.
An input shaft guide sleeve 17 is sleeved on the tail part of the pedal input shaft 24. A push rod spring 18 is fitted over the input shaft guide sleeve 17. An axial mounting hole 46 is formed in the rear end surface of the pedal input shaft 24. A ball plunger 22 is riveted into the axial mounting hole 46. A push rod spring seat 20 is rotatably fitted over the ball push rod 22. One end of the push rod spring 18 is sleeved on the input shaft guide sleeve 17, and the other end is sleeved on the push rod spring seat 20. A dust cover 19 is fitted around the outer circumference of the pusher spring 18. The tail part of the ball head push rod 22 is fixedly provided with a push rod fork 21 through a locking nut 23. The push rod fork 21 is connected to a brake pedal of the vehicle.
After reading this specification, it will be apparent to those skilled in the art that the present invention is formed by a combination of prior art, and some of these prior art forming each part of the present invention are described in detail herein, and some are not described in detail for the sake of brevity of the specification, but will be known to those skilled in the art after reading this specification. Moreover, it will be appreciated by those skilled in the art that the combination of these prior art techniques to form the present invention is highly creative and is a crystal that has been analyzed theoretically and experimented for many years by the inventor. It will also be apparent to those skilled in the art from this disclosure that each of the embodiments disclosed herein, and any combination of features, can be incorporated into the present invention.