CN210258386U - Distributed braking system with multiple working modes - Google Patents

Abstract

The utility model provides a distributed braking system with multiple mode. The distributed brake system comprises a brake pedal, manual cylinders, a brake controller, a power supply and at least three electric cylinders electrically connected with the brake controller, wherein the electric cylinders are respectively connected with a liquid drainage hole of the manual cylinders through brake pipelines, the electric cylinders are correspondingly connected to the same number of wheel brakes on an automobile one by one, and each electric cylinder and one corresponding wheel brake form a brake loop; the utility model discloses both satisfied the autonomic braking requirement of autopilot vehicle, still can realize braking energy recovery maximize under the prerequisite is felt not influencing brake pedal, have the dual redundant function of electronic redundant failure protection and the backup braking of manpower simultaneously. The utility model has the advantages of compact structure, control are nimble, the braking response is fast, brake pressure control accuracy is high, the failure protection ability is reliable, low in manufacturing cost, make intelligent driving car motion stationarity good when braking, and the reliability is high.

Description

Distributed braking system with multiple working modes

Technical Field

The utility model relates to an automobile brake system technical field, concretely relates to distributed brake system with multiple mode such as autonomic braking, drive-by-wire braking, helping hand braking and manpower backup braking.

Background

The automobile brake system is closely related to the automobile driving safety. In a conventional hydraulic brake system for an automobile, a driver applies a braking pressure to wheel cylinders of brakes of respective wheels by pressing a brake pedal, thereby braking and decelerating the automobile. Intelligent automotive systems such as Advanced Driving Assistance Systems (ADAS) and Automatic Driving Systems (ADS) require that the braking system be capable of applying autonomous braking to the vehicle, i.e., applying braking to some or all of the wheels without depressing the brake pedal. At present, most of brake systems capable of implementing autonomous braking adopt electric power assistance, and brake control devices such as a brake pedal are reserved. With the development of unmanned logistics distribution vehicles, an autonomous braking system applicable to ADS, which does not require a brake operating device, has been proposed.

Distributed braking systems have many advantages and are considered the direction of development for the next generation of braking systems. The braking force of all wheels can be independently controlled and adjusted, so that the distributed braking system has the advantages of flexible control, high braking force control precision and the like; the actuating mechanism of the distributed braking system is close to the wheel brake, so that the braking response is fast and the dynamic characteristic of the braking pressure is good; compared with the traditional double-loop brake system, the four-wheel independent brake distributed brake system is equivalent to a four-loop system, and the reliability of the system is further improved.

On the other hand, electric vehicles are also receiving wide attention from various countries. There are several countries that have published a schedule of prohibited fuel vehicles in sequence around the world in 2018, for example the netherlands and norway will prohibit fuel vehicles in 2025, india will prohibit the sale of fuel vehicles in 2030, and the uk and france will also prohibit the sale of fuel vehicles in full in 2040. China will also stop selling fuel cars completely in 2035. The automobile with the new energy possibly replacing the fuel automobile is a new energy automobile such as an electric automobile, a fuel cell automobile and the like. In order to increase the endurance mileage of a new energy automobile, braking energy recovery is commonly adopted. However, the existing brake system does not satisfy the requirement of braking energy recovery, i.e., cannot solve the contradiction between the brake pedal feel and the braking energy recovery. The reason for this is that existing brake systems are not decoupled at all.

Therefore, the existing brake system is no longer suitable for the braking requirements of intelligent automobiles and new energy automobiles, and a novel brake system needs to be provided to meet the requirements.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a distributed braking system with multiple mode such as autonomic braking, drive-by-wire braking, helping hand braking and manpower backup braking to satisfy intelligent automobile's autonomic braking needs, support new energy automobile's braking energy recovery simultaneously, realize braking energy recovery maximize under the prerequisite is felt at the brake pedal not influenced promptly.

In order to achieve the above object, the present invention provides a distributed braking system with multiple operating modes, including a brake pedal, a manual cylinder, a brake controller and a power supply, and further including at least three electric cylinders electrically connected to the brake controller, wherein the electric cylinders are respectively connected to drain holes of the manual cylinder through brake pipes, the electric cylinders are connected to wheel brakes of the same number on an automobile in a one-to-one correspondence manner, and each electric cylinder and a corresponding wheel brake form a brake loop;

the electric cylinder includes:

an electric cylinder body; the electric cylinder body is fixedly connected with the shell, the shell is provided with a motor, the motor drives the piston to slide through a pushing device, and the pushing device comprises a pushing rod driven by the motor; a through hole is formed in the middle of the piston, and the push rod movably penetrates through the through hole and forms an oil liquid channel for oil supply liquid to pass through with the inner side wall of the through hole; the push rod is provided with an input valve and an output valve on two sides of the through hole respectively, and a return elastic piece is arranged between the end part of the push rod penetrating through the through hole and the electric cylinder body; the electric cylinder body is provided with the oil inlet and the oil outlet on two sides of the piston respectively;

the brake controller is respectively connected with the pedal stroke sensor and the pressure sensor through signal wires and is used for measuring the stroke of the brake pedal and the pressure of the manual cylinder.

Furthermore, the pushing device is a ball screw pair comprising a nut and a pushing rod, and the pushing rod is a screw rod; the screw rod is provided with a first conical surface and a second conical surface which are respectively arranged on two sides of the through hole and are matched with the piston to open and close the oil passage; the first conical surface is matched with a third conical surface arranged on the piston to form the input valve, and the second conical surface is matched with a fourth conical surface arranged on the piston to form the output valve; the first conical surface tapers toward the piston and the second conical surface tapers away from the piston; when the return elastic piece is in a pre-pressing state, the output valve is closed, and the input valve is opened.

Furthermore, the interior of the shell is of a cylindrical hollow structure and comprises a first cylindrical cavity, a second cylindrical cavity and a third cylindrical cavity, the inner diameters of the first cylindrical cavity, the second cylindrical cavity and the third cylindrical cavity are sequentially increased, a partition surface is arranged between the first cylindrical cavity and the second cylindrical cavity, and a through hole for the screw rod to pass through is formed in the partition surface; a shaft shoulder is formed between the second cylindrical cavity and the third cylindrical cavity, the nut is rotatably arranged in the third cylindrical cavity, and one end of the nut is fixed on the shaft shoulder through a bearing; one end of the shell, which is close to the piston, extends outwards in the radial direction to form a boss, and the boss is in sealing fit with and fixedly connected with the opening of the electric cylinder body.

Further, an annular bottom surface is arranged between the first conical surface and the second conical surface of the screw rod, and the diameter of the annular bottom surface is smaller than the inner diameter of the through hole.

Further, the screw rod is provided with a guide groove, and one end of a guide pin fixed in the shell is inserted into the guide groove.

Further, the manual cylinder includes:

the end cover of the manual cylinder is internally provided with a rack which is connected with a brake pedal through a push rod fixed on the rack, the rack is meshed with a gear supported in the end cover, and the rotation of the gear around the axis of the gear outputs a corner signal through the pedal stroke sensor;

the manual cylinder body is provided with an elastic piece between the rack and the manual cylinder body; the manual cylinder body is internally provided with a front piston and a rear piston which are connected, the rack is abutted against the end cover under the pre-pressure action of the elastic piece and has an idle stroke with the rear piston; the front piston is provided with a front leather cup, a return elastic piece is arranged between the front piston and the front end surface of the manual cylinder body, and the front leather cup is positioned between the liquid supply hole and the compensation hole under the pre-pressure of the return elastic piece; the manual cylinder body is provided with the liquid discharge hole.

Furthermore, one side of the rear piston, which faces the rack, is provided with an insertion hole, and the rack is provided with a top part which is in insertion fit with the insertion hole; and under the action of the pre-pressure of the elastic piece of the manual cylinder, the idle stroke exists between the end surface of the abutting part and the bottom surface of the insertion hole of the rack.

Furthermore, the insertion hole is a cylindrical hole, the bottom surface of the cylindrical hole is in a concave spherical surface shape, the abutting part is a cylinder, and the end surface is in a convex spherical surface shape.

Furthermore, the number of the electric cylinders is four, and the electric cylinders comprise a first electric cylinder, a second electric cylinder, a third electric cylinder and a fourth electric cylinder, wherein the first electric cylinder and the first brake are communicated through a brake pipeline to form a first brake loop, the second electric cylinder and the second brake are communicated through a brake pipeline to form a second brake loop, the third electric cylinder and the third brake are communicated through a brake pipeline to form a third brake loop, and the fourth electric cylinder and the fourth brake are communicated through a brake pipeline to form a fourth brake loop.

Due to the adoption of the technical scheme, the utility model has the advantages of it is following:

1. the distributed brake system with multiple working modes of the utility model directly drives the electric cylinder piston by the motor through the transmission device, thereby having short pressure building time and fast brake response;

2. the utility model discloses distributed braking system with multiple working modes can realize ideal front and rear brake braking force distribution;

3. the utility model discloses distributed braking system with multiple working modes adopts four independent and redundant electro-hydraulic autonomous braking circuits, so braking system's reliability is high, the fail-safe ability is strong;

4. the utility model discloses the manpower jar small stroke drive-by-wire of distributed braking system with multiple working modes makes braking system support the demand of the maximum recovery of braking energy under the prerequisite that does not influence driver's brake pedal feel;

5. the utility model discloses distributed braking system with multiple mode provides the backup braking of inefficacy manpower, has further improved braking system's reliability and driving safety nature.

Drawings

FIG. 1 is a schematic structural diagram of a brake system with multiple operating modes according to the present invention;

FIG. 2 is a schematic structural view of the man-powered cylinder and the operating device thereof;

fig. 3 is a schematic structural view of the electric cylinder of the present invention;

FIG. 4 is an enlarged view taken at A in FIG. 3;

fig. 5 is an enlarged view of the opening F2 of the present invention at a;

the parts in the figures are numbered: 1-brake pedal; 2-a bearing pin; 3-pedal stroke sensor; 4-a manual vat; 5-a pressure sensor; 6-a power supply; 7-a brake controller; 8 a-a first electric cylinder; 8 b-a second electric cylinder; 8 c-a third electric cylinder; 8 d-a fourth electric cylinder; 9-a first brake; 10-a second brake; 11-a third brake; 12-a fourth brake; 401-a push rod; 402-a lock nut; 403-rack bar; 404-an end cap; 405-a gear; 406-a resilient member; 407-a spacing pin; 408-rear piston; 409-rear leather cup; 410-manual cylinder body; 411-a liquid supply hole; 412-compensation holes; 413-a spring; 414-front piston; 415-front leather cup; 416-drain hole; 417-a liquid storage tank; b-a jack; c-a top-butting portion; s-idle stroke; 801-electric machine; 802-coupling; 803-a retainer ring; 804-a nut; 805-bearings; 806-screw rod; 807-O-rings; 808-an oil inlet; 809-an oil inlet cavity; 810-guide pins; 811-sealing ring; 812-a leather cup; 813-piston; 814-an oil outlet; 815-return elastic member; 816-oil outlet chamber; 817-electric cylinder block; 818-a housing; v1-first conical surface; v2-second conical surface; v3-third cone; v4-fourth conical surface; v5-circular bottom surface; f1-input valve; f2-output valve; d-a cylindrical surface;

in fig. 1, the broken lines indicate signal lines and power supply lines; the thick solid line represents the brake pipe.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Example one

As shown in fig. 1, the utility model provides a distributed braking system with multiple mode mainly includes brake pedal 1, manpower jar 4, brake controller 7 and power 6, still include at least three with the electronic jar that brake controller 2 electricity is connected, electronic jar respectively through the brake pipe way with the outage 416 of manpower jar 4 links, electronic jar one-to-one is connected to the same number's on the car wheel brake, and every electronic jar forms a braking circuit with a wheel brake that corresponds. The brake controller 7 is respectively connected with the pedal stroke sensor 3 and the pressure sensor 5 through signal lines and is used for measuring the stroke of the brake pedal 1 and the pressure of the manual cylinder 4; the brake pedal 1 is coupled with the manual cylinder 4 through the support pin 2; the brake controller 7 is connected to the power source 6 and the motor 801 of the electric cylinder through power lines.

In this embodiment, the first electric cylinder 8a and the first brake 9 are communicated through a brake pipe to form a first brake circuit, the second electric cylinder 8b and the second brake 10 are communicated through a brake pipe to form a second brake circuit, the third electric cylinder 8c and the third brake 11 are communicated through a brake pipe to form a third brake circuit, and the fourth electric cylinder 8d and the fourth brake 12 are communicated through a brake pipe to form a fourth brake circuit; the first electric cylinder 8a, the second electric cylinder 8b, the third electric cylinder 8c and the fourth electric cylinder 8d are respectively connected with a drain hole 416 of the manual cylinder 4 through brake pipelines and are respectively connected with the brake controller 2 through signal lines.

In this embodiment, the first electric cylinder 8a, the second electric cylinder 8b, the third electric cylinder 8c, and the fourth electric cylinder 8d have the same structure as that shown in fig. 3, and include a motor 801, a coupling 802, a retainer 803, a nut 804, a bearing 805, a lead screw 806, an O-ring 807, a guide pin 810, a seal ring 811, a cup 812, a piston 813, a return elastic member 815, an electric cylinder 817, and a housing 818.

As shown in fig. 3, the electric cylinder includes an electric cylinder block 817; the electric cylinder 817 is fixedly connected with the housing 818, a motor 801 is arranged on the housing 818, the motor 801 drives the piston 813 to slide through a pushing device, and the pushing device comprises a pushing rod driven by the motor 801; a through hole is formed in the middle of the piston 813, and the push rod movably penetrates through the through hole and forms an oil liquid channel for oil to pass through with the inner side wall of the through hole; an input valve F1 and an output valve F2 are respectively arranged on two sides of the push rod positioned in the through hole, and a return elastic member 815 is arranged between the end part of the push rod penetrating through the through hole and the electric cylinder 817; the electric cylinder block 817 is provided with the oil inlet 808 and the oil outlet 814 at two sides of the piston 813 respectively.

In this embodiment, the resilient return element 815 is a return spring.

In this embodiment, the pushing device is a ball screw pair including a nut 804 and a pushing rod, and the pushing rod is a screw 806; the screw rod 806 is provided with a first conical surface V1 and a second conical surface V2 which are respectively arranged on two sides of the through hole and are matched with the piston 813 to open and close the oil passage; as shown in fig. 4 and 5, the first conical surface V1 cooperates with a third conical surface V3 provided on the piston 813 to form the input valve F1, and the second conical surface V2 cooperates with a fourth conical surface V4 provided on the piston 813 to form the output valve F2; the first conical surface V1 tapers toward the piston 813, and the second conical surface V2 tapers away from the piston 813; when the return elastic member 815 is in a pre-stressed state, the output valve F2 is closed, and the input valve F1 is opened.

In this embodiment, the length of the cylindrical surface D between the input valve F1 and the output valve F2 is 0.5-1mm longer than the length of the cylindrical surface of the through hole of the piston 813.

In this embodiment, the outer diameters of the first conical surface V1 and the second conical surface V2 are larger than the diameter of the through hole of the piston 813, so that the screw rod 806 can be divided into two sections and connected by screw threads, and the piston 813 is clamped between the first conical surface V1 and the second conical surface V2 and locked by screw threads when being installed.

In this embodiment, the screw rod 806 is provided with an annular bottom surface V5 between the first conical surface V1 and the second conical surface V2, and the diameter of the annular bottom surface V5 is smaller than the inner diameter of the through hole.

In this embodiment, the inside of the housing 818 is a cylindrical hollow structure, and includes a first cylindrical cavity, a second cylindrical cavity and a third cylindrical cavity, the inner diameters of which are sequentially increased, a partition surface is disposed between the first cylindrical cavity and the second cylindrical cavity, and a through hole for the screw rod 806 to pass through is formed on the partition surface; a shaft shoulder is formed between the second cylindrical cavity and the third cylindrical cavity, the nut 804 is rotatably arranged in the third cylindrical cavity, and one end of the nut 804 is fixed on the shaft shoulder through a bearing 805; the end of the housing 818 adjacent to the piston 813 extends radially outward to form a boss that sealingly engages and is fixedly attached to the opening of the cylinder block 817.

In this embodiment, the inner wall between the first cylindrical cavity and the second cylindrical cavity extends radially inward to form the partition surface, and the retainer 803 is mounted on the third cylindrical cavity.

In this embodiment, the electric cylinder 817 is a hollow cylinder with an open right end.

In this embodiment, the motor 801 is mounted on the right end face of the housing 818, and the output shaft of the motor 801 is coupled to the nut 804 through a coupling 802; is supported by the ball screw pair via two bearings 805 on the housing 818 and is axially positioned by a shoulder of the internal bore of the housing 818 and the retainer 803.

In this embodiment, the screw rod 806 is provided with a guide slot, one end of a guide pin 810 fixed in the housing 818 is inserted into the guide slot, and the guide pin 810 limits the rotation of the screw rod 806, so the working mode of the ball screw pair is the rotation of the nut 804 and the translation of the screw rod 806.

In this embodiment, a cup 812 with a one-way sealing function is mounted in an annular groove on the outer circumference of the piston 813, and is supported with the piston 813 in the inner hole of the electric cylinder 817 in an axially slidable manner.

In this embodiment, an oil chamber 816 is formed between the left end surface of the piston 813 and the interior of the electric cylinder 817, and the pre-pressure of the return elastic member 815 acts on one end of the screw rod 806, so that the output valve F2 is closed and the piston 813 is pressed against the end surface of the housing 818; an oil inlet cavity 809 is formed between the right end surface of the piston 813 and the first cylindrical cavity of the housing 818, the left end surface of the partition surface and the outer surface of the screw rod 806.

As shown in fig. 2, the manual cylinder 4 comprises a push rod 401, a rack 403, a lock nut 402, an end cover 404, a gear 405, an elastic member 406, a limit pin 407, a rear piston 408, a rear leather cup 409, a manual cylinder body 410, a liquid supply hole 411, a compensation hole 412, a spring 413, a front piston 414, a front leather cup 415, a liquid discharge hole 416 and a liquid storage tank 417; a rack 403 is arranged in an end cover 404 of the manual cylinder 4, the rack 403 is connected with the brake pedal 1 through a push rod 401 fixed on the rack 403, the rack 403 is meshed with a gear 405 supported in the end cover 404, and rotation of the gear 405 around the axis thereof outputs a rotation angle signal through the pedal stroke sensor 3;

the manual cylinder body 410, an elastic piece 406 is arranged between the rack 403 and the manual cylinder body 410; the inside of the manual cylinder 410 is provided with a front piston 414 and a rear piston 408 which are connected, the rack 403 abuts against the end cover 404 under the pre-pressure of the elastic member 406, and has an idle stroke S with the rear piston 408; a front leather cup 415 is arranged on the front piston 414, a spring 413 is arranged between the front piston 414 and the front end surface of the manual cylinder 410, and under the pre-pressure of the spring 413, the front leather cup 415 is positioned between the liquid supply hole 411 and the compensation hole 412; the manual cylinder block 410 is provided with the drain hole 416.

In this embodiment, a jack B is disposed on one side of the rear piston 408 facing the rack 403, and the rack 403 has a top C engaged with the jack B; under the pre-pressure action of the elastic piece 406 of the manual cylinder 4, the rack 403 has the idle stroke S between the end surface of the abutting part and the bottom surface of the insertion hole.

In this embodiment, the front end of the rear piston 408 is provided with an external thread, which is screwed into the central threaded hole of the front piston 414 to form a piston assembly and is located in the inner hole of the manual cylinder 410.

In this embodiment, the brake controller 7 is also connected to other electronic control systems (such as an anti-lock brake system or a smart car control system) shown in fig. 1 through a signal line.

In this embodiment, the brake controller 7 controls the motor 801 to operate to output a brake pressure to the corresponding brake according to the displacement measured by the pedal stroke sensor 3 or a brake request from another electronic control system. The driver braking demand is typically reflected by the pedal stroke sensor 3.

In this embodiment, the utility model discloses a distributed braking system with multiple mode mainly includes following several kinds of modes, i.e. brake-by-wire, helping hand braking, autonomic braking, failure protection braking and the backup braking of the manpower that became invalid etc.. The operation of the brake system in each of the operating modes is explained below.

1. Brake control method and working process in brake-by-wire mode

As shown in fig. 2, when the stroke of the brake pedal 1 is small, the system operates in the brake-by-wire mode. When the brake pedal 1 is depressed, the idle stroke S (see fig. 2) is gradually reduced. When the idle stroke S is not completely eliminated, the pedal force is not transmitted to the piston assembly, i.e. the brake pedal 1 is decoupled from the manual cylinder 4 and the wheel brakes.

In the brake-by-wire mode with a small pedal stroke, the braking forces required by the first brake 9, the second brake 10, the third brake 11, and the fourth brake 12 are normally provided by the first electric cylinder 8a, the second electric cylinder 8b, the third electric cylinder 8c, and the fourth electric cylinder 8 d. The specific working process is as follows: the brake controller 7 receives the signal of the pedal stroke sensor 3, calculates the required braking force and the target current of the motor 801, sends an instruction to the motor 801 to rotate the braking force and the target current and output torque, and drives the ball screw pair through the coupler 802 to enable the screw 806 to translate leftwards; after the thrust force of the screw 806 overcomes the pre-pressure of the return elastic member 815, the first conical surface V1 is attached to the third conical surface V3, the second conical surface V2 is spaced from the fourth conical surface V4, at this time, the input valve F1 is closed, the output valve F2 is opened, the screw 806 moves along the axial direction together with the piston 813, so that the volume of the oil outlet cavity 816 is reduced, and then the output pressure is delivered to the inlets of the brakes through the oil outlet 814 and the brake pipelines; meanwhile, the volume of the oil inlet cavity 809 is increased, and the required brake fluid is supplemented to the oil inlet cavity 809 through the compensation hole 412, the front cavity of the manual cylinder 4, the liquid discharge hole 416, the brake pipeline and the oil inlet 808 by the liquid storage tank 417; if the brake pedal 1 is released, the pedal stroke measured by the pedal stroke sensor 3 is reduced in the process, the brake controller 7 reduces the target current of the motor 801 accordingly, the torque of the motor 801 and the thrust acting on the screw rod 806 and the piston 813 are reduced accordingly, because the end surface of the piston 813 on the side of the oil outlet cavity 816 is subjected to a larger force at the time, the piston 813 moves to the right in the axial direction together with the screw rod 806, the volume of the oil outlet cavity 816 is increased, the brake pressure is reduced, the nut 804, the coupler 802 and the motor 801 are forced to rotate reversely, and the excess brake fluid in the oil inlet cavity 809 returns to the reservoir 417; if the brake pedal 1 is completely released, the braking is released, at this time, the pedal stroke measured by the pedal stroke sensor 3 is zero, the brake controller 7 accordingly stops the operation of the motor 801, the screw rod 806 moves in the reverse direction together with the piston 813 to return to the initial position under the action of the return elastic member 815, the output valve F2 is closed, the input valve F1 is opened, the braking of the brake is released, and the excess brake fluid in the oil inlet chamber 809 returns to the reservoir 417.

2. Brake control method and working process in power-assisted brake mode

When the brake pedal stroke is increased to eliminate the idle stroke S and further increase the brake pedal stroke, the pedal force can be directly transmitted to the piston assembly of the manual cylinder 4 and the manual cylinder 4 has pressure output, and the system works in a power-assisted braking mode. The specific working process is as follows: after the idle stroke S is eliminated, when S is equal to 0, the brake pedal force acts on the piston assembly through the support pin 2, the push rod 401 and the rack 403 and moves forward, the forward piston 414 moves forward to drive the leather cup 415 to move forward, the leather cup 415 covers the compensation hole 412, the liquid discharge hole 416 outputs pressure, and the pressure is transmitted to the oil inlet cavity 809 through a brake pipeline and the oil inlet 808 and acts on the piston 813; during the initial stage of the power-assisted braking, the output valve F2 is in a closed state under the pre-pressure of the return elastic member 815; the brake controller 7 calculates a target current of the motor 801 according to a pedal stroke signal and a preset power-assisted characteristic curve, drives the motor 801 to work, drives the ball screw pair to apply a thrust to the screw 806 through the coupler 802, overcomes the pre-pressure of the return elastic member 815, and closes the input valve F1 and opens the output valve F2; after the input valve F1 is closed, the pushing force transmitted to the screw rod 806 by the motor 801 acts on the piston 813 through the input valve F1 in a closed state; at this time, the force acting on the piston 813 includes both the pedal force transmitted to the oil inlet cavity 809 through the manual cylinder 4 and the brake pipeline and the motor force transmitted to the screw rod 806 through the coupler 802 and the nut 804, the piston 813 moves axially under the combined action of the pedal force and the motor torque, the volume of the oil outlet cavity 816 is reduced, and the generated pressure is output to a corresponding brake through the brake pipeline, so that the power-assisted braking is realized; when the brake pedal 1 is released in the power-assisted braking mode, the pedal force and the hydraulic pressure acting on the piston 813 are both reduced, and the pedal stroke measured by the pedal stroke sensor 3 is reduced, so that the brake controller 7 reduces the target current of the motor 801 accordingly, the torque of the motor 801 and the thrust acting on the lead screw 806 and the piston 813 are both reduced, so that the oil outlet cavity 816 and the brake pressure are reduced accordingly, the nut 804, the coupling 802 and the motor 801 are forced to rotate reversely, and the redundant brake fluid in the oil inlet cavity 809 returns to the reservoir 417; if the brake pedal 1 is released sufficiently in the power-assisted braking mode, resulting in an idle stroke S >0 in fig. 2, the system is switched from the power-assisted braking mode to the brake-by-wire mode.

3. Brake control method and working process in autonomous brake mode

When the brake controller 7 receives a brake request from other electronic control systems, the system works in an autonomous braking mode. The specific working process in the autonomous braking mode is as follows: the brake controller 7 calculates a target torque of the motor 801 according to received brake requests from other electric control systems, and then respectively sends torque commands to the motor 801 to control each electric cylinder to work, so that the brake is automatically braked; the control in the brake-by-wire mode depends on the magnitude of the pedal stroke, and the control in the autonomous braking mode depends on the braking request from other electronic control systems, except that the working process in the two modes is the same.

4. Brake control method and working process in failure protection brake mode

When one brake circuit fails, the system operates in a fail-safe braking mode.

When the brake controller 7 detects that one brake circuit of the system fails, failure protection braking can be implemented by applying a target torque larger than that of the motor of the non-failed brake circuit when the system normally works; at this time, the brake controller 7 first calculates a target assist force or a target braking force according to a pedal stroke sensor signal or a braking request from another electronic control system, then distributes the target assist force or the target braking force to each brake of the non-failed brake circuit, and then controls the electric cylinder output torque of the non-failed brake circuit, thereby realizing fail-safe braking. In determining the target assistance or target braking force for each brake in the fail-safe braking mode, the maximum torque of the respective electric machine should not be exceeded or, according to a particular embodiment and with reference to relevant regulatory requirements, be determined.

The brake release in the fail safe brake mode is the same as the autonomous brake mode and the like.

5. Working process in failure manpower backup braking mode

If the electric control braking function of the braking system is completely lost due to any fault, namely, the four braking circuits cannot generate effective braking action by depending on the work of the motor 801, the manual backup braking can be implemented. In the failed manual backup braking mode, if a driver steps on the brake pedal 1, the pedal force pushes the piston assembly of the manual cylinder 4 through the support pin 2, the push rod 401 and the rack 403, and the braking pressure established by the manual cylinder 4 is transmitted to the oil inlet cavity 809 through a braking pipeline. Because the motor 801 does not work, the output valve F2 of the electric cylinder is closed, and therefore the oil inlet cavity 809 and the oil outlet cavity 816 of the electric cylinder are in a brake fluid isolation state; at this time, the piston 813 is moved by the pressure from the manual cylinder 4 in the oil inlet chamber 809, and the pressure generated in the oil outlet chamber 816 is output to the brake through the brake pipe, so that the manual backup brake is applied.

The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and to implement the present invention, so as not to limit the protection scope of the present invention, and all equivalent changes or modifications made according to the spirit of the present invention should be covered by the protection scope of the present invention.

Claims (9)

1. A distributed braking system with multiple working modes comprises a brake pedal (1), a manual cylinder (4), a brake controller (7) and a power supply (6), and is characterized by further comprising at least three electric cylinders electrically connected with the brake controller (7), wherein the electric cylinders are respectively connected with a liquid discharge hole (416) of the manual cylinder (4) through brake pipelines, the electric cylinders are correspondingly connected to the same number of wheel brakes on an automobile one by one, and each electric cylinder and one corresponding wheel brake form a brake loop;

the electric cylinder includes:

an electric cylinder block (817); the electric cylinder body (817) is fixedly connected with the shell (818), a motor (801) is arranged on the shell (818), the motor (801) drives the piston (813) to slide through a pushing device, and the pushing device comprises a pushing rod driven by the motor (801); a through hole is formed in the middle of the piston (813), and the push rod movably penetrates through the through hole and forms an oil liquid channel for oil to pass through with the inner side wall of the through hole; an input valve (F1) and an output valve (F2) which are communicated with the oil liquid channel are respectively arranged on two sides of the push rod which are positioned on the through hole, and a return elastic element (815) is arranged between the end part of the push rod which penetrates through the through hole and the electric cylinder body (817); an oil inlet (808) and an oil outlet (814) are respectively formed in the two sides of the piston (813) of the electric cylinder body (817);

the brake controller (7) is respectively connected with the pedal stroke sensor (3) and the pressure sensor (5) through signal lines and is used for measuring the stroke of the brake pedal (1) and the pressure of the manual cylinder (4).

2. A distributed braking system with multiple operating modes as claimed in claim 1 wherein the pushing means is a ball screw pair comprising a nut (804) and a push rod, the push rod being a screw (806); the screw rod (806) is provided with a first conical surface (V1) and a second conical surface (V2) which are respectively arranged on two sides of the through hole and matched with the piston (813) to open and close the oil passage; the first conical surface (V1) cooperates with a third conical surface (V3) arranged on the piston (813) to form the input valve (F1), and the second conical surface (V2) cooperates with a fourth conical surface (V4) arranged on the piston (813) to form the output valve (F2); the first conical surface (V1) tapers towards the piston (813) and the second conical surface (V2) tapers away from the piston (813); when the return elastic member (815) is in a pre-stressed state, the output valve (F2) is closed, and the input valve (F1) is opened.

3. The distributed brake system with multiple working modes according to claim 2, wherein the inside of the housing (818) is a cylindrical hollow structure, the inside of the housing comprises a first cylindrical cavity, a second cylindrical cavity and a third cylindrical cavity, the inner diameters of the first cylindrical cavity, the second cylindrical cavity and the third cylindrical cavity are sequentially increased, a partition surface is arranged between the first cylindrical cavity and the second cylindrical cavity, and a through hole for the screw rod (806) to pass through is formed in the partition surface; a shaft shoulder is formed between the second cylindrical cavity and the third cylindrical cavity, the nut (804) is rotatably arranged in the third cylindrical cavity, and one end of the nut (804) is fixed on the shaft shoulder through a bearing (805); one end of the shell (818) close to the piston (813) extends outwards in the radial direction to form a boss, and the boss is matched with the opening of the electric cylinder body (817) in a sealing mode and fixedly connected with the opening.

4. A distributed braking system with several modes of operation according to claim 2, characterized in that said screw (806) is provided with an annular bottom surface (V5) between said first conical surface (V1) and said second conical surface (V2), said annular bottom surface (V5) having a diameter smaller than the inner diameter of said through hole.

5. A distributed braking system with multiple operating modes as claimed in claim 2 wherein the lead screw (806) is provided with a guide slot into which one end of a guide pin (810) fixed in the housing (818) is inserted.

6. A distributed braking system with multiple operating modes according to claim 1, characterized in that the manual cylinder (4) comprises:

the end cover (404), a rack (403) is arranged in the end cover (404) of the manual cylinder (4), the rack (403) is connected with the brake pedal (1) through a push rod (401) fixed on the rack, the rack (403) is meshed with a gear (405) supported in the end cover (404), and the rotation of the gear (405) around the axis thereof outputs a rotation angle signal through the pedal stroke sensor (3);

the manual cylinder body (410), an elastic piece (406) is arranged between the rack (403) and the manual cylinder body (410); a front piston (414) and a rear piston (408) which are connected are arranged in the manual cylinder body (410), the rack (403) abuts against the end cover (404) under the pre-pressure action of the elastic piece (406), and the rack and the rear piston (408) have an idle stroke (S); a front leather cup (415) is arranged on the front piston (414), a spring (413) is arranged between the front piston (414) and the front end face of the manual cylinder body (410), and under the pre-pressure of the spring (413), the front leather cup (415) is positioned between the liquid supply hole (411) and the compensation hole (412); the manual cylinder body (410) is provided with the liquid discharge hole (416).

7. The distributed brake system with multiple working modes according to claim 6, wherein a plug hole (B) is formed in one side, facing the rack (403), of the rear piston (408), and a butting part (C) which is in plugging fit with the plug hole (B) is arranged on the rack (403); and under the pre-pressure action of an elastic piece (406) of the manual cylinder (4), the idle stroke (S) exists between the end surface of the abutting part and the bottom surface of the insertion hole of the rack (403).

8. The distributed brake system with multiple operating modes as claimed in claim 7, wherein the insertion hole (B) is a cylindrical hole, the bottom surface of the cylindrical hole is concave spherical, the abutting portion (C) is a cylinder, and the end surface is convex spherical.

9. The distributed brake system with multiple working modes according to any one of claims 1 to 8, wherein the number of the electric cylinders is four, and the electric cylinders comprise a first electric cylinder (8a), a second electric cylinder (8b), a third electric cylinder (8c) and a fourth electric cylinder (8d), the first electric cylinder (8a) is communicated with the first brake (9) through a brake pipeline to form a first brake loop, the second electric cylinder (8b) is communicated with the second brake (10) through a brake pipeline to form a second brake loop, the third electric cylinder (8c) is communicated with the third brake (11) through a brake pipeline to form a third brake loop, and the fourth electric cylinder (8d) is communicated with the fourth brake (12) through a brake pipeline to form a fourth brake loop.

Images