CN115285095B

CN115285095B - Electromechanical braking system and vehicle

Info

Publication number: CN115285095B
Application number: CN202211079533.4A
Authority: CN
Inventors: 何浴辉; 倪辉
Original assignee: Huawei Digital Power Technologies Co Ltd
Current assignee: Huawei Digital Power Technologies Co Ltd
Priority date: 2022-09-05
Filing date: 2022-09-05
Publication date: 2024-03-01
Anticipated expiration: 2042-09-05
Also published as: CN115285095A

Abstract

The embodiment of the application provides an electromechanical braking system and a vehicle. The system comprises: the electromechanical braking device comprises an electronic driving assembly and a mechanical transmission assembly, wherein the mechanical transmission assembly comprises a rotating piece and a moving piece; a mechanical braking device and a switching mechanism; the electronic mechanical braking device and the switching mechanism work normally, the switching mechanism is in a first state, the mechanical braking device is separated from the brake pedal, and the brake pedal is stepped to enable the electronic driving assembly to drive the rotating piece to rotate so as to drive the moving piece to move and enable the braking piece to brake; the electronic mechanical braking device and/or the switching mechanism is/are disabled, the switching mechanism is in a second state, the mechanical braking device is connected with the brake pedal, and the mechanical braking device outputs linear motion when the brake pedal is stepped on and is connected with the moving piece so as to drive the moving piece to move to brake the braking piece. The electronic mechanical brake is mechanically backed up and braked, the working safety and reliability of the system are improved, the number of parts is small, the structure is simple, and the cost is reduced.

Description

Electromechanical braking system and vehicle

Technical Field

The present application relates to the field of braking technology, and in particular, to an electromechanical braking system and a vehicle.

Background

In order to ensure the use safety, hydraulic or electrohydraulic braking systems are provided with hydraulic backup braking. In the conventional hydraulic braking system, the hydraulic pushing piston pushes the friction plate to move towards the friction plate so as to contact with the friction plate, so that braking can be realized.

Unlike traditional hydraulic braking system, the electronic mechanical brake (electronic mechanical brake, EMB) adopts the mode of combining electronics and machinery to brake, and the motor can be used as a driving mechanism for braking, and small-size and light-weight electric wires can be used as signal and energy conducting media, namely, hydraulic pipelines and brake fluid are omitted, and electric energy is used as braking energy source, so that the hydraulic braking system has the advantages of stable braking performance, light weight, rapid response, safety, environmental protection and the like.

However, when the EMB fails, such as electrical failure, braking cannot be performed normally, resulting in lower safety and reliability of the system operation. Alternatively, the conventional brake backup mechanism of the EMB is complicated in structure, resulting in an increase in cost.

Disclosure of Invention

The embodiment of the application provides an electromechanical braking system and a vehicle, which realize mechanical backup of electromechanical braking, and can brake when the electromechanical braking cannot work normally, so that the safety and the reliability of system work are improved, the number of mechanical backup parts is less, the structure is simple, and the cost is reduced.

For this purpose, the following technical solutions are adopted in the embodiments of the present application:

in a first aspect, embodiments of the present application provide an electromechanical braking system comprising: the electronic mechanical braking device comprises an electronic driving assembly and a mechanical transmission assembly, wherein the mechanical transmission assembly comprises a rotating piece and a moving piece in transmission connection with the rotating piece, and the moving piece is used for being connected with a braking piece; the mechanical braking device is detachably connected with the brake pedal in a transmission way, and the switching mechanism is in a first state or a second state; wherein: when the electronic mechanical braking device and the switching mechanism work normally, the switching mechanism is in the first state, the mechanical braking device is respectively connected with the moving part and the brake pedal in a transmission way, and the electronic driving assembly is used for driving the rotating part to rotate when the brake pedal is stepped on so as to drive the moving part to move and enable the brake part to brake; when the electronic mechanical braking device and/or the switching mechanism fails, the switching mechanism is in the second state, the mechanical braking device is in transmission connection with the brake pedal, and the mechanical braking device is used for outputting linear motion when the brake pedal is stepped on and in transmission connection with the moving piece so as to drive the moving piece to move, so that the braking piece brakes.

In the electromechanical braking system of the embodiment of the application, when the electromechanical braking device and/or the switching mechanism fails, for example, an electronic driving component of the electromechanical braking device, the switching mechanism and the like fail electrically, so that the switching mechanism is in a second state, or a mechanical transmission component of the electromechanical braking device fails, the switching mechanism can be fed back to a controller in the electronic driving component at the moment, then the switching mechanism is in the second state through the controller, in the second state, the mechanical braking device is in transmission connection with a brake pedal, and the mechanical braking device can output linear motion when the brake pedal is stepped on and is in transmission connection with a moving part so as to drive the moving part to move to brake the braking part, thereby realizing mechanical backup braking on the electromechanical braking, improving the safety and reliability of the system, and being easy to realize, having fewer parts and simple structure and being beneficial to reducing the cost.

In one possible implementation manner, the rotating member includes a gear, and the moving member includes a rack, and a through hole extending along a moving direction of the rack is provided on the rack; the mechanical braking device comprises a conversion mechanism, a cable and a pull rod, wherein the pull rod is arranged in the through hole and in clearance fit with the through hole, the length of the pull rod is larger than that of the through hole, one end of the pull rod is connected with the first end of the cable, the other end of the pull rod is provided with a boss, the boss is in limit fit with the through hole, and the second end of the cable is connected with the conversion mechanism; in the second state, the brake pedal is in driving connection with the switching mechanism, and the switching mechanism is used for switching the movement of the brake pedal into the movement of the pull rod through the cable, wherein: when the brake pedal is stepped on, the cable pulls the pull rod to move, and the boss drives the moving part to move, so that the brake part brakes. That is, in this implementation, when the brake pedal is depressed, the cable is pulled by the switching mechanism to move the pull rod, and then the rack is driven to move, and the brake member is connected to the rack, so that the brake member can be moved to brake.

In one possible implementation manner, a step hole is formed in the end, close to the boss, of the through hole, and the boss is accommodated in the step hole so as to achieve limit fit; or, the two ends of the through hole along the length direction are respectively provided with a step hole, and the boss is accommodated in the step hole at the end part of the through hole, which is close to the boss, so as to realize limit fit. That is, in this implementation, the rack may reciprocate, and the boss may overlap the end of the through hole to achieve a limit fit, in order to reduce the path size of the reciprocating movement of the rack, a stepped hole may be provided at the end of the through hole near the boss to accommodate the boss, and the outer end surface of the boss may be flush with the corresponding end surface of the rack when the boss is accommodated in the stepped hole.

In one possible implementation, the mechanical braking device further comprises an elastic element, in the second state: when the brake pedal is stepped on, the elastic piece deforms along with the movement of the pull rod; when the brake pedal is released, the restoring force of the elastic piece enables the pull rod to restore. That is, in this embodiment, in order to enable the automatic return of the tie rod upon release of the brake pedal, an elastic member may be provided, and the elastic member is configured to deform upon depression of the brake pedal so as to provide a return force upon release of the brake pedal.

In one possible implementation manner, the mechanical braking device further comprises a shell, the shell comprises a first cavity, the mechanical braking device further comprises a connecting piece, the connecting piece is arranged in the first cavity, the first cavity comprises a first retaining wall and a second retaining wall which are arranged at intervals along the length direction, the first end of the cable penetrates through the first retaining wall and stretches into the first cavity to be connected with one end of the connecting piece, one end of the pull rod penetrates through the second retaining wall and stretches into the first cavity to be connected with the other end of the connecting piece, a flange is arranged on the periphery of the connecting piece, the elastic piece is arranged in the first cavity, one end of the elastic piece abuts against the flange, and the other end of the elastic piece abuts against the first retaining wall; in the second state: the brake pedal is stepped on, so that the conversion mechanism pulls the cable to drive the connecting piece and the pull rod to move towards the first retaining wall, and the elastic piece is compressed; and the connecting piece and the pull rod move away from the first retaining wall under the action of the restoring force of the elastic piece so as to restore. That is, in this implementation, in order to enable the elastic member to be deformed when the brake pedal is depressed, both ends of the connecting member may be connected to the tie rod and the cable, respectively, and the connecting member and the elastic member may be disposed in the first chamber of the housing, and the elastic member may be disposed between the outer peripheral flange of the connecting member and the first blocking wall of the first chamber, which is far away from the tie rod, so that when the brake pedal is depressed to cause the cable to pull the rail, the connecting member moves the compressible elastic member toward the first blocking wall, and when the brake pedal is released, the restoring force of the elastic member may push the connecting member and the tie rod in a direction far away from the first blocking wall, enabling the tie rod to be restored.

In one possible implementation, a portion of the side wall of the first chamber in the circumferential direction is open; or, the first chamber comprises at least two parts along the circumferential direction, and the at least two parts are spliced to form a circumferential closed structure. That is, in this implementation, in order to facilitate the installation of the connection member and the elastic member, a portion of the side wall of the first chamber may be opened, or the first chamber may be composed of at least two portions, so that the connection member and the elastic member may be installed in one portion first, and the other portion may be spliced with the one portion to form a circumferential closed structure, thereby better protecting the elastic member and the connection member and preventing foreign objects such as dust from entering the first chamber.

In one possible implementation, the housing includes a second chamber, the second blocking wall is located between the first chamber and the second chamber, and the rotating member, the moving member, and the pull rod are disposed in the second chamber. That is, in this embodiment, in order to protect the rotary member, the moving member and the tie rod, a second chamber may be provided on the housing to mount the rotary member, the moving member and the tie rod, and an output shaft of a reduction gearbox to be described below may also extend into the second chamber to be connected with the rotary member.

In one possible implementation, the mechanical braking device further comprises a housing within which the cable is movably disposed; the shell comprises a third chamber, the first blocking wall is positioned between the first chamber and the third chamber, the end part of the third chamber, which is far away from the first chamber, is open, and one end of the tube shell is arranged in the third chamber; the shell is provided with a stop piece, the other end of the shell abuts against the stop piece, and the second end of the cable penetrates through the stop piece and is connected with the conversion mechanism. That is, in this implementation, a cartridge may be provided at the middle portion of the cable in order to protect the cable and reduce friction.

In one possible implementation, the switching mechanism is in driving connection with the brake pedal, the electromechanical brake system further comprising a feedback mechanism, the switching mechanism being in disengageable driving connection with the feedback mechanism, wherein: in the first state, the switching mechanism is in transmission connection with the feedback mechanism and is disconnected with the mechanical braking device, and the feedback mechanism simulates pedal stepping force when the brake pedal is stepped on; in the second state, the switching mechanism is in transmission connection with the feedback mechanism, is in transmission connection with the mechanical braking device, and outputs linear motion when the brake pedal is stepped on. In other words, in this embodiment, the switching mechanism can be connected in a drive manner to the feedback mechanism (first state) or to the mechanical brake (second state), and, as a result of the switching mechanism being connected in a drive manner to the brake pedal, the feedback mechanism or the mechanical brake can be moved when the brake pedal is depressed.

In one possible implementation, the feedback mechanism includes a coil spring, a first rack, a first rotating shaft, and a first gear and a first reel disposed on the first rotating shaft, the first rack is meshed with the first gear, the coil spring is disposed in the first reel, and the first rotating shaft is rotatably disposed on the housing; the conversion mechanism of the mechanical braking device comprises a second rack, a second rotating shaft, a second gear and a second reel wheel, wherein the second gear and the second reel wheel are arranged on the second rotating shaft, the second rack is meshed with the second gear, the second rotating shaft is rotatably arranged on the shell, and the cable is connected with the second reel wheel; the switching mechanism comprises an electromagnetic device, double-sided ratchets and a position adjusting device, wherein the failure of the switching mechanism comprises the electrical failure of the electromagnetic device, the double-sided ratchets are in transmission connection with the brake pedal, and the double-sided ratchets are pushed to move when the brake pedal is trampled, wherein: in the first state, the electromagnetic device works normally, the position adjusting device is linked with the electromagnetic device to enable the double-sided ratchet to be located at a first position, in the first position, a first side ratchet of the double-sided ratchet is meshed with the first rack, and a second side ratchet of the double-sided ratchet is disengaged from the second rack; in the second state, the electromagnetic device fails, the position adjustment device enables the double-sided ratchet to be located at a second position, in the second position, a first side ratchet of the double-sided ratchet is disengaged from the first rack, and a second side ratchet of the double-sided ratchet is engaged with the second rack. That is, in this implementation, the feedback mechanism is similar to the switching mechanism of the mechanical brake device in that the second reel of the switching mechanism is connected to the cable, the coil spring is not required to be provided in the second reel, and the first reel of the feedback mechanism is not connected to the cable, but the coil spring may be provided in the first reel thereof to simulate the pedal stepping force.

In one possible implementation manner, the electronic driving assembly comprises an electronic signal sensor, a controller, a driving part and a reduction gearbox, wherein the output end of the driving part is in transmission connection with the input end of the reduction gearbox, the output end of the reduction gearbox is in transmission connection with the rotating part, when the brake pedal is stepped on to brake, the electronic signal sensor sends a braking signal to the controller, and the controller controls the driving part to drive the rotating part to rotate according to the braking signal. That is, in this implementation manner, the electronic signal sensor may be, for example, a displacement sensor, and when the brake pedal is depressed, the electronic signal sensor may form a brake signal according to the detected displacement, and send the brake signal to the controller, and the controller may control the driving member to rotate according to the brake signal, and drive the rotating member to rotate through the reduction gearbox, so as to drive the moving member and the brake member to move.

In one possible implementation, the mechanical transmission assembly further includes a power transmission mechanism, an input end of the power transmission mechanism is connected to the moving member, an output end of the power transmission mechanism is used for being connected to the braking member, and the power transmission mechanism is used for converting movement of the moving member into movement of the braking member at a required position. That is, in this implementation, in order to enable the stopper at a desired position to move, a power transmission mechanism may be provided between the moving member and the stopper so as to convert the movement of the moving member into the movement of the stopper.

In a second aspect, embodiments of the present application provide a vehicle including: the electromechanical brake system provided in the first aspect above; a brake pedal in transmission connection with the electromechanical brake system; the braking device comprises a braking part and a friction disc, wherein the friction disc is arranged on the wheel, the braking part is connected with a moving part of the electromechanical braking system, and the moving part is moved when the braking pedal is stepped on, so that the braking part is driven to move towards the friction disc and contact the friction disc to brake.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The drawings that accompany the detailed description can be briefly described as follows.

FIG. 1 is a schematic diagram of an electromechanical brake system with mechanical backup braking;

FIG. 2 is a schematic diagram of an exemplary architecture of the electromechanical brake system shown in FIG. 1;

fig. 3 is a schematic structural diagram of an electromechanical brake system according to an embodiment of the present disclosure;

FIG. 4 is a schematic view of the electromechanical brake system shown in FIG. 3 in a first state;

Fig. 5 is a schematic diagram showing a specific structure of the electro-mechanical brake system shown in fig. 3 in a second state.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

In the description of the present application, the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate an orientation or positional relationship based on that shown in the drawings, merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

In the description of the present application, unless explicitly stated and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, a fixed connection, a removable connection, an interference connection, or an integral connection; the specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

Furthermore, in the description of the present specification, a particular feature, structure, material, or characteristic may be combined in any suitable manner in one or more embodiments.

Conventional hydraulic brake systems are typically provided with hydraulic backup brakes. In a conventional hydraulic braking system, when an electric failure occurs (e.g., an electric motor or an electromagnetic valve fails), a brake pedal is depressed to push a hydraulic master cylinder, so that brake fluid enters a wheel cylinder through two normally open valves and four normally open valves at wheel ends, thereby generating emergency backup braking.

The electronic mechanical brake EMB is braked in an electronic and mechanical combination mode, and when the EMB fails, such as electrical failure, normal braking cannot be performed, so that the system is low in working safety and reliability. Alternatively, the brake backup mechanism of the EMB is complicated in structure, resulting in an increase in cost.

Fig. 1 is a schematic structural diagram of an electromechanical brake system with mechanical backup braking. As shown in fig. 1, the electromechanical brake system includes a brake 1, a switching mechanism 2, a brake pedal 3, an electronic brake mechanism, a mechanical brake mechanism (i.e., mechanical backup brake), and a feedback mechanism 6. The broken line a is an electric brake mechanism transmission path, the solid line b is a mechanical brake mechanism transmission path, and the solid line c is a feedback mechanism transmission path. The electronic brake mechanism may include a controller 4 and an electronic signal sensor 5. The mechanical brake mechanism (not shown) may include a transmission portion and an implement portion. The brake 1 may include a motor, a reduction gearbox and a braking section. An output shaft of the motor is in transmission connection with a reduction gearbox, and an output shaft of the reduction gearbox is connected with a braking part; wherein, the controller 4 is connected with the motor electricity, and the executive part is connected with the output shaft of reducing gear box. The switching mechanism 2 has a first state and a second state, the switching mechanism 2 is in the first state when the electric brake mechanism is normally operated, and the switching mechanism 2 is in the second state when the electric brake mechanism is not normally operated.

When the switching mechanism 2 is in the first state, the electronic signal sensor 5 can receive a braking signal of the brake pedal 3 and can transmit the braking signal to the controller 4, so that the controller 4 can control the brake 1 to brake according to the braking signal, and the feedback mechanism 6 can be in transmission connection with the brake pedal to simulate pedal stepping force; when the switching mechanism 2 is in the second state, the brake pedal 3 is disconnected from the feedback mechanism 6 and connected to the transmission part, the actuating part is connected to the brake pedal 3 via the transmission part, and the actuating part is also connected to the brake 1 for braking the brake 1.

That is, the switching mechanism 2 is in a first state (e.g., when the electric is normal), and the electric brake mechanism is connectable to the brake pedal 3 and the brake 1 so that the electric brake mechanism can brake the service; the switching mechanism 2 is in a second state (for example, when the electric failure occurs), the mechanical braking mechanism, namely, the mechanical backup brake, can be connected with the brake pedal 3 and the brake 1, so that the mechanical braking mechanism can brake the running, and the running safety performance is ensured. In addition, the mechanical braking mechanism has no hydraulic structure, so that the electromechanical braking system can be provided with no stepped piston, oil circuit and other structures, the complexity of the electromechanical braking system structure is reduced, and the electromechanical braking system has lower cost.

FIG. 2 is a schematic diagram of an exemplary architecture of the electromechanical brake system shown in FIG. 1. As shown in fig. 2, the electro-mechanical brake system includes an EMB and a rotating parallel mechanism (mechanical backup brake). The EMB may include a motor, a reduction gearbox, and a ball screw in sequential driving connection. The rotating parallel mechanism is connected with an output shaft of the reduction gearbox. When EMB braking failure occurs, the rotating parallel mechanism can brake, specifically, the stepping on the brake pedal can enable the rotating parallel mechanism to drive the output shaft of the reduction gearbox to rotate, and then the screw in the ball screw is enabled to rotate, so that the nut in the ball screw moves, the nut in the ball screw is connected with the friction plate, and the friction plate can be driven to move towards the friction plate and contact with the friction plate, so that braking is achieved.

That is, the EMB may use a wheel end motor to drive the reduction gearbox to rotate a rotating member such as a screw of the rotary straightening assembly, so as to move a nut of the moving member such as a ball screw, and further move the nut to drive the friction plate to generate braking. In fig. 2, the rotation parallel mechanism is backed up at the rotation position of the rotation converting assembly, and the rotation parallel mechanism outputs the rotation motion, so that the output shaft of the reduction gearbox can rotate, and the friction plate is driven to move through the ball screw to brake. The brake pedal is stepped on, so that the linear motion needs to be converted into rotation, the structure of the parallel rotating mechanism is complex, the number of parts is large, the assembly is inconvenient, the cost is reduced, and the friction plate needs to perform linear motion during braking, so that the rotation needs to be converted into movement again, namely the parallel rotating mechanism needs to drive the rotating part to rotate, the rotating part drives the moving part to move again, the movement conversion is complex, and the time for realizing braking is relatively long.

In view of this, the present embodiments provide an electromechanical braking system and a vehicle. The vehicle includes an electromechanical braking system. The electromechanical braking system designs a simpler maintenance-free purely mechanical backup braking mechanism, realizes mechanical backup braking on the electromechanical braking, and can perform mechanical backup braking when the electromechanical braking cannot work normally, so that the safety and reliability of system work are improved, the number of mechanical backup braking parts is less, the structure is simple, and the cost is reduced.

Fig. 3 is a schematic structural diagram of an electromechanical brake system according to an embodiment of the present application. As shown in fig. 3, the electro-mechanical brake system includes an EMB and a straight parallel mechanism (mechanical backup). The EMB comprises a motor, a reduction gearbox and a rotary variable-linear assembly which are sequentially connected in a transmission mode. The linear parallel mechanism is connected with the moving part of the rotary linear-to-linear assembly, when EMB braking failure occurs, the linear parallel mechanism can brake, specifically, stepping on the brake pedal can enable the linear parallel mechanism to drive the moving part in the rotary linear-to-linear assembly to move, and the moving part can drive the braking part such as the friction plate to move towards the friction disc and contact with the friction plate, so that braking is achieved. The movement of the brake pedal can be converted into the movement of the linear parallel mechanism, so that the linear parallel mechanism drives the moving part and the brake part to move for braking.

The linear parallel mechanism is arranged on the linear motion section of the rotary linear changing assembly, so that the linear parallel mechanism is simple in structure, few in parts and convenient and time-saving to assemble, and is beneficial to reducing cost.

Fig. 4 is a schematic diagram showing a specific structure of the electro-mechanical brake system shown in fig. 3 in a first state. Fig. 5 is a schematic diagram showing a specific structure of the electro-mechanical brake system shown in fig. 3 in a second state. As shown in fig. 4 and 5, the electro-mechanical brake system includes an electro-mechanical brake apparatus 1, a mechanical brake apparatus 2, and a switching mechanism 3. The electromechanical brake apparatus 1 includes an electronic drive assembly 11 and a mechanical transmission assembly 12. The mechanical transmission assembly 12 may include a rotating member 121 and a moving member 122 drivingly connected to the rotating member 121, the moving member 122 being adapted to be connected to a braking member.

The mechanical transmission assembly 12 may further include a power transmission mechanism (not shown) having an input coupled to the moving member 122 and an output coupled to the braking member, the power transmission mechanism being configured to convert movement of the moving member 122 into movement of the braking member at a desired location. The power transmission mechanism can be one of the parts such as a sliding block, a lever (with a fulcrum), a push rod (needing to bear pressure), a pull rod (needing to bear tension) or the like, or the combination of the parts.

The electromechanical brake system is applicable to a vehicle. The vehicle may further comprise a brake pedal B, wheels and a braking device. In fig. 4 and 5, the brake pedal B is also shown. The brake pedal B is in driving connection with an electromechanical brake system, such as a switching mechanism 3. The braking device may include a braking member and a friction disc (not shown), the friction disc is disposed on the wheel, the braking member may be a friction disc, the braking member is connected with the moving member 122 of the mechanical transmission assembly 12, and when the braking pedal B is stepped on, the moving member 122 is moved, so as to drive the braking member to move towards the friction disc and contact the friction disc to perform braking.

The electronic drive assembly 11 may include an electronic signal sensor 111, a controller 112, a driver 113, and a reduction gearbox 114. The driving member 113 may include an electric motor or a hydraulic motor. The output end of the driving piece 113 is in transmission connection with the input end of the reduction gearbox 114, the output end of the reduction gearbox 114 is in transmission connection with the rotating piece 121, and when the brake pedal B is stepped on to brake, the electronic signal sensor 111 sends a braking signal to the controller 112, and the controller 112 controls the driving piece 113 to drive the rotating piece 121 to rotate according to the braking signal. Among them, the electronic signal sensor 111 may be a displacement sensor, and may generate a brake signal by detecting movement of the brake pedal B.

The mechanical brake 2 is in releasable driving connection with a brake pedal. The switching mechanism 3 is in a first state (i.e. electromechanical braking state) or a second state (i.e. mechanical backup braking state). As shown in fig. 4, when the electromechanical brake apparatus 1 and the switching mechanism 3 are both operating normally, the switching mechanism 3 is in the first state, and the electromechanical brake apparatus 2 is disengaged from the transmission connection with the moving member 122 and the brake pedal B, respectively. When the brake pedal B is depressed, the electronic driving assembly 11 drives the rotating member 121 to rotate, so as to drive the moving member 122 to move, and the braking member brakes. As shown in fig. 5, when the electromechanical brake device 1 and/or the switching mechanism 3 fail, the switching mechanism 3 is in the second state, the mechanical brake device 2 is in transmission connection with the brake pedal B, and the mechanical brake device 2 is used for outputting linear motion when the brake pedal B is stepped on and in transmission connection with the moving member 122, so as to drive the moving member 122 to move to brake the braking member. In addition, in both the first state and the second state, when the brake pedal B is stepped on to move the moving member 122, the moving member 122 can drive the brake member, i.e. the friction plate, to move towards the friction disc and contact the friction disc, so as to realize braking, and when the brake pedal B is released, the moving member 122 can drive the brake member, i.e. the friction plate, to move away from the friction disc, so as to be separated from the friction disc.

The "normal operation" of both the electromechanical brake device 1 and the switching mechanism 3 may mean that the electronic driving component 11 of the electromechanical brake device 1 is electrically normal, the mechanical transmission component 12 is not failed, and the switching mechanism 3 is electrically normal. The electromechanical brake apparatus 1 failure may include an electrical failure of the electric drive assembly 11 and/or a failure of the mechanical transmission assembly 12, and the switching mechanism 3 failure mainly refers to an electrical failure of an electromagnetic device (described below) of the switching mechanism 3. When the electronic drive assembly 11 fails electrically and the electromagnetic device of the switching mechanism 3 fails electrically, the switching mechanism 3 may be caused to be in the second state directly; when the mechanical transmission assembly 12 fails, the controller 112 in the electronic driving assembly 11 may be notified first, and then the controller 112 switches the switching mechanism 3 to the second state. That is, the second state (i.e., the mechanical backup braking) is performed in both an active mode, in which the software issues an active switching command for functional safety reasons (e.g., the mechanical transmission assembly 12 fails, the controller 112 controls the switching mechanism 3 to switch to the second state), and a passive mode, in which the electrical failure, in which the switching mechanism 3 is powered off, is performed, and the switching mechanism 3 is passively switched to the second state.

According to the electromechanical braking system, when the electromechanical braking device 1 and/or the switching mechanism 3 fail, the switching mechanism 3 is in the second state, the mechanical braking device 2 is in transmission connection with the brake pedal B, and the mechanical braking device 2 is used for outputting linear motion when stepping on the brake pedal B and is in transmission connection with the moving piece 122 so as to drive the moving piece 122 to move to brake the braking piece, so that mechanical backup braking is carried out on the electromechanical braking, the working safety and the reliability of the system are improved, the structure is easy to realize, the number of parts is small, the structure is simple, and the cost is reduced.

The rotating member 121 and the moving member 122 may be one of a gear and a rack, a ball screw mechanism, a cam mechanism, and a crank block mechanism, and in this application, a gear and a rack will be mainly described as an example. Specifically, with continued reference to fig. 4 and 5, the rotation member 121 may include a gear, and the movement member 122 may include a rack provided with a through hole K extending in a movement direction of the rack. The mechanical brake 2 comprises a switching mechanism 21, a cable 22 and a pull rod 23. The cable 22 may be a steel cable. The pull rod 23 is disposed in the through hole K and is in clearance fit with the through hole K.

And, the length of pull rod 23 can be greater than the length of through-hole K, and the one end of pull rod 23 is connected with the first end of cable 22, and the other end of pull rod 23 is provided with boss T, boss T and the spacing cooperation of through-hole K, overlap joint outside if boss T and through-hole K to realize spacing cooperation. The second end of the cable 22 is connected to the switching mechanism 21. In the second state, the brake pedal B is in driving connection with the switching mechanism 21, and the switching mechanism 21 is used to switch the movement of the brake pedal B into the movement of the pull rod 23 via the cable 22. When the brake pedal B is stepped on, the cable 22 pulls the pull rod 23 to move, and the boss T drives the moving part 122 to move, so that the brake part brakes.

Assuming that the mechanical transmission assembly 12 has not failed, electrical health and electrical failure are described below as examples. When the brake pedal B is depressed, the electronic driving assembly 11 of the electromechanical brake apparatus 1 drives the gear, i.e., the rotating member 121, to rotate, thereby driving the rack, i.e., the moving member 122, to move linearly, and the moving member 122 pushes the brake member, i.e., the friction plate, into contact with the friction disc through a power transmission mechanism (not shown) such as a lever and a crank, thereby generating braking. Because the pull rod 23 is in clearance fit with the through hole K, the pull rod 23 is not driven to move when the electronic driving assembly 11 drives the moving piece 122 to move for braking; when the electricity fails, the brake pedal B is stepped on, so that the cable 22 can pull the pull rod 23, the boss T at the tail end of the pull rod 23 can be in limit fit with the through hole K, and accordingly the moving piece 122 is pulled to move, the moving piece 122 drives the power transmission mechanism to move, and the brake piece such as a friction plate is pushed to contact with the friction disc, so that backup braking is generated. That is, the pull rod 23 and the moving member 122 (i.e. the EMB linear motion mechanism) are in clearance fit to form a unidirectional coupling, the pull rod 23 can pull the EMB linear motion mechanism, i.e. the moving member 122, whereas the EMB linear motion mechanism cannot pull the pull rod 23 to move, so that when the moving member 122 moves in the first state, the mechanical brake device 2, such as the pull rod 23, does not interfere with the moving member 122, and the transmission connection is disengaged.

Because the boss T can be lapped on the outer side of the through hole K to realize limit fit, considering that the rack can reciprocate, in order to reduce the size of the reciprocating path of the rack and reduce the volume, the end part of the through hole K, which is close to the boss T, can be provided with a step hole J, and the boss T is accommodated in the step hole J to realize limit fit; or, two ends of the through hole K along the length direction can be respectively provided with a step hole J, and the boss T is accommodated in the step hole J at the end part of the through hole K, which is close to the boss T, so as to realize limit fit. And, the outer end surface of the boss T may be made flush with the corresponding end surface of the rack when the boss T is accommodated in the stepped hole J.

In addition, the mechanical braking device 2 may further comprise an elastic member 24, in the second state: when the brake pedal B is depressed, the elastic member 24 deforms as the tie rod 23 moves; when the brake pedal B is released, the restoring force of the elastic member 24 returns the tie rod 23.

Specifically, the electromechanical brake system may further include a housing 4, the housing 4 includes a first chamber P1, the mechanical brake device 2 further includes a connecting member 25, the connecting member 25 is disposed in the first chamber P1, the first chamber P1 includes a first blocking wall D1 and a second blocking wall D2 disposed at intervals along a length direction, a first end of the cable 22 is disposed on the first blocking wall D1 and extends into the first chamber P1 to be connected with one end of the connecting member 25, and one end of the pull rod 23 is disposed on the second blocking wall D2 and extends into the first chamber P1 to be connected with the other end of the connecting member 25.

In one example, one end of the pull rod 23 may be screw-coupled with the other end of the connection member 25 for easy installation and removal, and in particular, one end of the pull rod 23 may be provided with external screw threads, and the other end of the connection member 25 may be provided with a screw hole matching the external screw threads of the pull rod 23. In addition, the outer periphery of the connecting member 25 may be provided with a flange, the elastic member 24 is disposed in the first chamber P1, and one end of the elastic member 24 abuts against the flange and the other end abuts against the first blocking wall D1. Wherein the elastic member 24 may be a spring, which may be sleeved at one end of the cable 22 and the connecting member 25.

In the second state: the brake pedal B is stepped, so that the switching mechanism 21 pulls the cable 22 to drive the connecting piece 25 and the pull rod 23 to move towards the first retaining wall D1, and the elastic piece 24 is compressed; the brake pedal B is released, and the link 25 and the tie rod 23 are moved away from the first blocking wall D1 by the restoring force of the elastic member 24 to be restored.

In order to facilitate the installation of the elastic member 24 and the connection member 25, a portion of the sidewall of the first chamber P1 in the circumferential direction may be opened. Alternatively, the first chamber P1 may include at least two portions along the circumferential direction, and the at least two portions are spliced to form a circumferential closed structure.

Further, the housing 4 may include a second chamber P2, the second blocking wall D2 is located between the first chamber P1 and the second chamber P2, and the rotating member 121, the moving member 122 and the pull rod 23 are disposed in the second chamber P2. Also, in order to reduce the volume of the second chamber P2, the mover 122 moves between a first end of the second chamber P2 and a second end of the second chamber P2, wherein: when the brake pedal B is depressed, the moving member 122 may be located at the first end of the second chamber P2, i.e. the second blocking wall D2; upon release of brake pedal B, mover 122 may be located at a second end of second chamber P2.

In addition, in order to protect the cable 22 and reduce frictional resistance when the cable 22 moves, the mechanical brake 2 may further include a housing 26, the cable 22 being movably disposed within the housing 26; the housing 4 comprises a third chamber P3, the first blocking wall D1 is located between the first chamber P1 and the third chamber P3, an end of the third chamber P3 far away from the first chamber P1 is open, and one end of the tube shell 26 is disposed in the third chamber P3; the housing 4 is provided with a stopper Z against which the other end of the tube housing 26 abuts, and the second end of the cable 22 passes through the stopper Z and is connected to the switching mechanism 21.

With continued reference to fig. 4 and 5, the switching mechanism 3 may be in driving connection with the brake pedal B, and the electromechanical brake system may further comprise a feedback mechanism 5, the switching mechanism 3 being in disengageable driving connection with the feedback mechanism 5. In the first state, the switching mechanism 3 can be in transmission connection with the feedback mechanism 5 and is disconnected from the mechanical braking device 2, and the feedback mechanism 5 simulates pedal stepping force when the brake pedal B is stepped on; in the second state, the switching mechanism 3 is disconnected from the feedback mechanism 5 and is in transmission connection with the mechanical braking device 2, and the mechanical braking device 2 outputs linear motion when the brake pedal B is stepped on.

In one example, the feedback mechanism 5 may include a coil spring (not shown in the drawings), a first rack 51, a first rotation shaft 52, and a first gear 53 and a first reel 54 provided on the first rotation shaft 52, the first rack 51 being engaged with the first gear 53, the coil spring being provided in the first reel 54, the first rotation shaft 52 being rotatably provided on the housing 4. The switching mechanism 21 of the mechanical brake 2 may include a second rack 211, a second rotating shaft 212, a second gear 213 disposed on the second rotating shaft 212, and a second reel 214, the second rack 211 is meshed with the second gear 213, the second rotating shaft 212 is rotatably disposed on the housing 4, and the cable 22 is connected with the second reel 214. And, the switching mechanism 3 can include an electromagnetic device 31, a double-sided ratchet 32 and a position adjusting device 33, the failure of the switching mechanism 3 includes the electrical failure of the electromagnetic device 31, the double-sided ratchet 32 is in transmission connection with a brake pedal B such as a pedal push rod, and the double-sided ratchet 32 can be pushed to move when the brake pedal B is stepped on.

As shown in fig. 4, in the first state, the electromagnetic device 31 is normally operated, the position adjustment device 33 is linked with the electromagnetic device 31 to enable the double-sided ratchet 32 to be located at the first position, and in the first position, the first-sided ratchet of the double-sided ratchet 32 is meshed with the first rack 51 of the feedback mechanism 5, so as to realize transmission connection, and the second-sided ratchet of the double-sided ratchet 32 is disengaged from the second rack 211. When the brake pedal B is stepped on, the double-sided ratchet 32 can push the first rack 51 to move so as to drive the first gear 53 to rotate, and then the first reel 54 is rotated, so that the coil spring is deformed, and the pedal stepping force is simulated.

As shown in fig. 5, in the second state, the electromagnetic device 31 fails, the position adjustment device 33 positions the double-sided ratchet 32 in the second position, in which the first-sided ratchet of the double-sided ratchet 32 is disengaged from the first rack 51 of the feedback mechanism 5, and the second-sided ratchet of the double-sided ratchet 32 is engaged with the second rack 211 of the switching mechanism 21 of the mechanical brake 2, achieving a driving connection. When the brake pedal B is stepped on, the double-sided ratchet 32 can push the second rack 211 to move to drive the second gear 213 to rotate, so that the second reel 214 rotates, and the cable 22 is wound on the second reel 214, so as to drive the pull rod 23 to move.

The position adjusting device 33 may include a first elastic member 331 and a metal driving member 332. In the first state, the metal driving member 332 overcomes the elastic force of the first elastic member 331 under the electromagnetic force of the electromagnetic device 31, so that the double-sided ratchet 32 is disengaged from the second rack 211 and engaged with the first rack 51; in the second state, the double-sided ratchet 32 is disengaged from the first rack 51 by the first elastic member 331 and engaged with the second rack 211.

In summary, according to the scheme of the embodiment of the application, the brake backup can be performed on the electronic mechanical brake EMB, the hydraulic backup mode is completely abandoned, the backup is performed in a purely mechanical mode, the number of parts of the mechanical backup mechanism (namely the mechanical brake mechanism/device) is small, the structure is simple and reliable, and the cost is reduced. When the EMB works normally, the mechanical backup mechanism is mechanically separated from the EMB, normal service braking is not affected/interfered, and the performance and safety of an anti-lock brake system (ABS)/electronic stability controller (electronic stability controller, ESC) on a low-adhesion road surface are ensured. When EMB can not work normally, the backup brake is generated by adopting a purely mechanical mode, namely, the mechanical backup mechanism is used for braking, the braking deceleration can reach or even exceed the regulation requirement, for example, the vehicle deceleration can reach 2.54m/s2, and the safety of vehicles and personnel is effectively ensured.

The last explanation is: the above embodiments are only for illustrating the technical solution of the present application, but are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An electromechanical braking system, comprising:

an electromechanical brake device (1) comprising an electronic drive assembly (11) and a mechanical transmission assembly (12), the mechanical transmission assembly (12) comprising a rotating member (121) and a moving member (122) in transmission connection with the rotating member (121), the moving member (122) being adapted to be connected with a brake member;

a mechanical brake device (2) and a switching mechanism (3), wherein the mechanical brake device (2) is detachably connected with a brake pedal in a transmission way, and the switching mechanism (3) is in a first state or a second state; wherein:

when the electromechanical brake device (1) and the switching mechanism (3) work normally, the switching mechanism (3) is in the first state, the mechanical brake device (2) is respectively in transmission connection with the moving part (122) and the brake pedal, and the electronic driving assembly (11) is used for driving the rotating part (121) to rotate when the brake pedal is stepped on so as to drive the moving part (122) to move and enable the brake part to brake;

When the electronic mechanical braking device (1) and/or the switching mechanism (3) fail, the switching mechanism (3) is in the second state, the mechanical braking device (2) is in transmission connection with the brake pedal, and the mechanical braking device (2) is used for outputting linear motion when the brake pedal is stepped on and is in transmission connection with the moving piece (122) so as to drive the moving piece (122) to move to enable the braking piece to brake.

2. The electromechanical brake system according to claim 1, characterized in that the rotating member (121) comprises a gear, and the moving member (122) comprises a rack provided with a through hole (K) extending in the moving direction of the rack; the mechanical braking device (2) comprises a conversion mechanism (21), a cable (22) and a pull rod (23), wherein the pull rod (23) is arranged in the through hole (K) and in clearance fit with the through hole (K), the length of the pull rod (23) is larger than that of the through hole (K), one end of the pull rod (23) is connected with the first end of the cable (22), a boss (T) is arranged at the other end of the pull rod (23), the boss (T) is in limit fit with the through hole (K), and the second end of the cable (22) is connected with the conversion mechanism (21);

In the second state, the brake pedal is in driving connection with the switching mechanism (21), and the switching mechanism (21) is used for switching the movement of the brake pedal into the movement of the pull rod (23) through the cable (22), wherein: when the brake pedal is stepped on, the cable (22) pulls the pull rod (23) to move, and the boss (T) drives the moving piece (122) to move, so that the brake piece brakes.

3. An electromechanical braking system according to claim 2, characterised in that:

the end part of the through hole (K) close to the boss (T) is provided with a step hole (J), and the boss (T) is accommodated in the step hole (J) so as to realize limit fit; or alternatively, the first and second heat exchangers may be,

the two ends of the through hole (K) along the length direction are respectively provided with a step hole (J), and the boss (T) is accommodated in the step hole (J) at the end part of the through hole (K) close to the boss (T) so as to realize limit fit.

4. An electromechanical braking system according to claim 2 or 3, characterised in that said mechanical braking device (2) further comprises an elastic member (24), in said second state:

when the brake pedal is stepped on, the elastic piece (24) deforms along with the movement of the pull rod (23);

When the brake pedal is released, the restoring force of the elastic piece (24) restores the pull rod (23).

5. The electromechanical brake system according to claim 4, characterized in that it further comprises a housing (4), said housing (4) comprising a first chamber (P1), said mechanical brake device (2) further comprising a connecting member (25), said connecting member (25) being arranged inside said first chamber (P1), said first chamber (P1) comprising a first blocking wall (D1) and a second blocking wall (D2) arranged at opposite intervals along the length direction, a first end of said cable (22) being threaded on said first blocking wall (D1) and extending into said first chamber (P1) to be connected with one end of said connecting member (25), one end of said pull rod (23) being threaded on said second blocking wall (D2) and extending into said first chamber (P1) to be connected with the other end of said connecting member (25), the outer circumference of said connecting member (25) being provided with a flange, said elastic member (24) being arranged inside said first chamber (P1) and abutting against said first end of said elastic member (24) against said first blocking wall (D1);

in the second state: the brake pedal is stepped on, so that the conversion mechanism (21) pulls the cable (22) to drive the connecting piece (25) and the pull rod (23) to move towards the first blocking wall (D1), and the elastic piece (24) is compressed; the brake pedal is released, and the connecting piece (25) and the pull rod (23) move away from the first blocking wall (D1) under the action of the restoring force of the elastic piece (24) so as to restore.

6. The electro-mechanical braking system of claim 5 wherein:

part of the side wall of the first chamber (P1) in the circumferential direction is open; or alternatively, the first and second heat exchangers may be,

the first chamber (P1) comprises at least two parts along the circumferential direction, and the at least two parts are spliced to form a circumferential closed structure.

7. Electromechanical braking system according to claim 5, characterized in that said housing (4) comprises a second chamber (P2), said second blocking wall (D2) being located between said first chamber (P1) and said second chamber (P2), said rotating member (121), said moving member (122) and said tie rod (23) being arranged inside said second chamber (P2).

8. The electromechanical brake system according to claim 5, characterized in that said mechanical brake arrangement (2) further comprises a housing (26), said cable (22) being movably arranged within said housing (26);

the shell (4) comprises a third chamber (P3), the first blocking wall (D1) is positioned between the first chamber (P1) and the third chamber (P3), the end part, far away from the first chamber (P1), of the third chamber (P3) is open, and one end of the tube shell (26) is arranged in the third chamber (P3); the shell (4) is provided with a stop piece (Z), the other end of the tube shell (26) abuts against the stop piece (Z), and the second end of the cable (22) penetrates through the stop piece (Z) and is connected with the conversion mechanism (21).

9. Electromechanical brake system according to claim 2, characterized in that the switching mechanism (3) is in driving connection with the brake pedal, the electromechanical brake system further comprising a feedback mechanism (5), the switching mechanism (3) being in disengageable driving connection with the feedback mechanism (5), wherein:

in the first state, the switching mechanism (3) is in transmission connection with the feedback mechanism (5) and is disconnected with the mechanical braking device (2), and the feedback mechanism (5) simulates pedal stepping force when the brake pedal is stepped on;

in the second state, the switching mechanism (3) is in transmission connection with the feedback mechanism (5) and in transmission connection with the mechanical braking device (2), and the mechanical braking device (2) outputs linear motion when the brake pedal is stepped on.

10. The electromechanical brake system according to claim 9, characterized in that the electromechanical brake system further comprises a housing (4), the feedback mechanism (5) comprising a coil spring, a first rack (51), a first spindle (52) and a first gear (53) arranged on the first spindle (52), a first reel (54), the first rack (51) being in engagement with the first gear (53), the coil spring being arranged in the first reel (54), the first spindle (52) being rotatably arranged on the housing (4);

The conversion mechanism (21) of the mechanical braking device (2) comprises a second rack (211), a second rotating shaft (212) and a second gear (213) and a second reel (214) which are arranged on the second rotating shaft (212), wherein the second rack (211) is meshed with the second gear (213), the second rotating shaft (212) is rotatably arranged on the shell (4), and the cable (22) is connected with the second reel (214);

the switching mechanism (3) comprises an electromagnetic device (31), a double-sided ratchet (32) and a position adjusting device (33), wherein the failure of the switching mechanism (3) comprises the electrical failure of the electromagnetic device (31), the double-sided ratchet (32) is in transmission connection with the brake pedal, and the double-sided ratchet (32) is pushed to move when the brake pedal is stepped on, wherein:

in the first state, the electromagnetic device (31) works normally, the position adjusting device (33) is linked with the electromagnetic device (31) to enable the double-sided ratchet (32) to be located at a first position, in the first position, a first side ratchet of the double-sided ratchet (32) is meshed with the first rack (51), and a second side ratchet of the double-sided ratchet (32) is disengaged from the second rack (211);

in the second state, the electromagnetic device (31) fails, the position adjustment device (33) enables the double-sided ratchet (32) to be located at a second position, in the second position, a first side ratchet of the double-sided ratchet (32) is disengaged from the first rack (51), and a second side ratchet of the double-sided ratchet (32) is engaged with the second rack (211).

11. An electromechanical brake system according to any of claims 1-3, characterised in that the electronic drive assembly (11) comprises an electronic signal sensor (111), a controller (112), a driving member (113) and a reduction gearbox (114), wherein the output end of the driving member (113) is in transmission connection with the input end of the reduction gearbox (114), the output end of the reduction gearbox (114) is in transmission connection with the rotating member (121), when the brake pedal is depressed for braking, the electronic signal sensor (111) sends a braking signal to the controller (112), and the controller (112) controls the driving member (113) to drive the rotating member (121) to rotate according to the braking signal.

12. An electromechanical brake system according to any of the claims 1-3, characterised in that the mechanical transmission assembly (12) further comprises a power transmission mechanism, the input of which is connected to the moving member (122), the output of which is adapted to be connected to the braking member, the power transmission mechanism being adapted to convert the movement of the moving member (122) into a movement of the braking member at a desired position.

13. A vehicle, characterized by comprising:

The electro-mechanical brake system of any one of claims 1-12;

a brake pedal (B) in transmission connection with the electromechanical brake system;

the braking device comprises a braking part and a friction disc, wherein the friction disc is arranged on the wheel, the braking part is connected with a moving part (122) of the electromechanical braking system, and when a brake pedal (B) is stepped on, the moving part (122) is moved, so that the braking part is driven to move towards the friction disc and contact the friction disc to brake.