Distributed drive-by-wire electro-hydraulic braking system

Abstract

The utility model provides a distributed drive-by-wire electro-hydraulic braking system, and belongs to the technical field of braking systems. The problems that an existing brake system leaks oil and is high in energy consumption are solved. A brake pedal position sensor, a wheel speed sensor and an electro-hydraulic actuator of the distributed drive-by-wire electro-hydraulic brake system are all electrically connected with a vehicle-mounted computer, the vehicle-mounted computer can control the electro-hydraulic actuator to work independently, the electro-hydraulic actuator comprises a servo motor and a two-dimensional pump, the two-dimensional pump comprises a shell and a brake piston, and the shell and the brake piston are electrically connected. A forward cavity and a backward cavity are formed between the two ends of the brake piston and the shell, the servo motor drives the two-dimensional pump to work to suck and discharge hydraulic oil from the backward cavity into the forward cavity so that the brake piston can move to apply braking force, and the servo motor drives the two-dimensional pump to work to suck and discharge the hydraulic oil from the forward cavity into the backward cavity so that the brake piston can move to relieve the braking force. The distributed drive-by-wire electro-hydraulic braking system has the advantages that each wheel is independently braked, the problem of liquid leakage of a braking pipeline is solved, and energy consumption is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of braking system technology and relates to a distributed wire-controlled electro-hydraulic braking system. Background Technology

[0002] The vehicle braking system is a core device that ensures vehicle driving safety. It achieves functions such as deceleration, stopping, and stable parking by applying a force opposite to the direction of travel.

[0003] Existing automotive braking systems, such as the hydraulic disc brake assembly caliper disclosed in Chinese patent literature [Patent Application No.: 201621033733.6; Authorization Announcement No.: CN206190774U], include a hydraulic pump, a caliper body, and disc brake pads. A hydraulic cylinder is installed inside the caliper body. The hydraulic pump and the hydraulic cylinder are connected by a hydraulic oil conduit. A hydraulic force plate is installed inside the hydraulic cylinder. A hydraulic working rod is installed on one side of the hydraulic force plate. A brake friction block is installed on one side of the disc brake pad, and a shock absorber is installed on the other side of the disc brake pad. The disc brake pad consists of a friction enhancement hole, a screw washer, a body connecting piece, a bearing protection cover, a vent hole, and a bearing fixing nut. The screw washer is installed in a ring inside the body connecting piece. A bearing protection cover is installed at the lower end of the body connecting piece, and a vent hole is provided inside the bearing protection cover.

[0004] In this type of caliper design, when the driver presses the brake pedal, the braking system transmits a signal to the hydraulic pump. The pump then pumps hydraulic fluid, which flows through hydraulic conduits into the hydraulic cylinder. The fluid in the cylinder compresses the hydraulic pressure plate, applying a thrust. The pressure plate transmits this thrust to the hydraulic working rod, causing it and the pressure plate to expand outwards. Simultaneously, the working rod pushes the brake friction pads, squeezing the friction disc brake pads to achieve braking. However, this type of caliper requires a central hydraulic pump connected to multiple hydraulic cylinders via multiple hydraulic conduits, enabling simultaneous braking of multiple wheels. The long hydraulic lines pose a risk of fluid leakage, and the pump needs to pre-load high-pressure oil, leading to pressure loss during distribution. Maintaining high pressure also requires higher energy consumption. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems in the existing technology by proposing a distributed wire-controlled electro-hydraulic braking system. The technical problem to be solved is how to enable each wheel to brake independently, eliminate the risk of brake line leakage, and reduce energy consumption.

[0006] The objective of this utility model can be achieved through the following technical solution: A distributed drive-by-wire electro-hydraulic braking system, comprising an on-board computer and several brake assemblies installed at the wheels, characterized in that it further comprises a brake pedal position sensor, several wheel speed sensors installed at the wheels for monitoring the wheel rotation speed, and an electro-hydraulic actuator disposed in the brake assemblies. The brake pedal position sensor, the wheel speed sensors, and the electro-hydraulic actuator are all electrically connected to the on-board computer. The on-board computer can control the electro-hydraulic actuator to work independently. The electro-hydraulic actuator includes a servo motor and a two-dimensional pump. The two-dimensional pump includes a housing and a brake piston slidably disposed within the housing. The brake piston has a forward chamber and a reverse chamber between its two ends and the housing. The servo motor drives the two-dimensional pump to draw hydraulic oil from the reverse chamber to the forward chamber, causing the brake piston to move to apply braking force. The servo motor drives the two-dimensional pump to draw hydraulic oil from the forward chamber to the reverse chamber, causing the brake piston to move to release the braking force.

[0007] The onboard computer is the electronic control unit of a car. When braking is needed, the driver presses the brake pedal, and the brake pedal position sensor transmits the pedal opening to the onboard computer. Simultaneously, the onboard computer receives and identifies the wheel speeds transmitted from the wheel speed sensors, and then controls each electro-hydraulic actuator to operate independently based on the received signals, achieving precise braking. Compared with existing centralized electro-hydraulic braking systems, distributed electromechanical braking systems, and drive-by-wire electromechanical brakes, this braking system adopts a distributed layout, utilizing the onboard computer to directly control the individual electro-hydraulic actuators, enabling independent braking of each wheel. This braking system eliminates the master cylinder and the oil pipes between the master and wheel cylinders, eliminating the risk of pipe leakage. It also eliminates the high-pressure oil pump and solenoid valve. During braking, the electro-hydraulic actuators pressurize the hydraulic fluid, solving the problems of pressure loss and high energy consumption caused by the main drive-by-wire brakes that require the pump to pre-store high-pressure oil and then distribute it to the wheel cylinders via the solenoid valve, thus reducing energy consumption.

[0008] In the aforementioned distributed wire-controlled electro-hydraulic braking system, the brake assembly includes a bracket, a caliper mounted on the bracket, and a pair of brake pads disposed within the bracket. An electro-hydraulic actuator is inserted and fixed within the caliper, and the actuator can move the brake pads. This type of brake assembly has a simple structure, with the electro-hydraulic actuator inserted and fixed within the caliper, making efficient use of space.

[0009] In the aforementioned distributed wire-controlled electro-hydraulic braking system, the two-dimensional pump further includes a pump piston that is slidably disposed within the brake piston and two end caps fixedly connected to the brake piston. Each of the two end caps has a cam groove on its outer side, and the two cam grooves are arranged with a 90-degree phase difference. The pump piston includes a main body and a pump shaft. The main body is located between the two end caps, and a non-communicating left chamber and a right chamber are formed between the main body and the two end caps. The brake piston has a left channel and a right channel. The left chamber communicates with the forward chamber through the right channel, and the right chamber communicates with the backward chamber through the left channel. Both ends of the pump shaft pass through the two end caps, and rollers that can slide along the cam grooves are respectively provided at both ends of the pump shaft. The servo motor is fixedly connected to the brake piston, and a coupling is provided between the output shaft of the servo motor and the pump shaft. The output shaft of the servo motor can drive the pump piston to rotate through the coupling, causing the rollers to slide along the cam grooves and the brake piston to partially extend out of the outer casing after axial movement.

[0010] During braking, the output shaft of the servo motor rotates, driving the pump piston to rotate via the coupling. This causes the roller to slide along the cam groove. Since the end cover is fixed, the cam groove is also fixed. The roller sliding along the cam groove moves the pump piston to the left, changing the volume of the forward chamber, reverse chamber, left chamber, and right chamber. This allows the oil in the left chamber to flow into the forward chamber through the right channel, and the oil in the reverse chamber to enter the right chamber through the left channel. This causes the brake piston to move to the left and partially extend out of the housing, pushing the brake pads to achieve braking. After the brake pedal is released, the output shaft of the servo motor rotates in the opposite direction, driving the pump piston to rotate in the opposite direction via the coupling. This causes the roller to slide in the opposite direction along the cam groove, moving the pump piston to the right. This changes the volume of the forward chamber, reverse chamber, left chamber, and right chamber, allowing the oil in the forward chamber to flow back into the left chamber through the right channel, and the oil in the right chamber to flow into the reverse chamber through the left channel. This returns both the brake piston and the pump piston to their original positions, completing one braking cycle.

[0011] In the aforementioned distributed wire-controlled electro-hydraulic braking system, the main body has a left transition groove and a right transition groove. The left chamber is connected to the right channel via the left transition groove, and the right chamber is connected to the left channel via the right transition groove. The transition between the left and right transition grooves allows the hydraulic fluid to circulate better and more precisely within the electro-hydraulic actuator, improving braking accuracy.

[0012] In the aforementioned distributed wire-controlled electro-hydraulic braking system, the coupling is cylindrical, and its sidewalls are provided with several elongated sliding grooves spaced at equal intervals along the axial direction of the pump shaft. The pump shaft is equipped with several pulleys, which are embedded in the sliding grooves and can move along them. This structure allows the pump shaft and the motor's output shaft to move relative to each other circumferentially and axially.

[0013] Compared with existing technologies, the distributed drive-by-wire electro-hydraulic braking system provided by this utility model adopts a distributed layout and uses the on-board computer to directly control the electro-hydraulic actuators to work independently, enabling independent braking of each wheel. This braking system eliminates the master cylinder and the oil pipe between the master cylinder and the wheel cylinders, thus solving the risk of pipeline leakage. At the same time, it eliminates the oil pump and solenoid valve. During braking, the electro-hydraulic actuator pressurizes the oil, solving the problems of pipeline pressure loss and high energy consumption caused by the main drive-by-wire brake having to store high-pressure oil in advance by the oil pump and then distribute it to the wheel cylinders by the solenoid valve, thereby reducing energy consumption. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the layout of this distributed wire-controlled electro-hydraulic braking system.

[0015] Figure 2 This is a cross-sectional view of the brake assembly and the electro-hydraulic actuator.

[0016] Figure 3 This is a cross-sectional view of the electro-hydraulic actuator.

[0017] Figure 4 This is an exploded view of part of the structure of this electro-hydraulic actuator.

[0018] In the diagram, 1. Onboard computer; 2. Wheel; 3. Brake assembly; 31. Bracket; 32. Caliper; 33. Brake pad; 4. Brake pedal position sensor; 5. Wheel speed sensor; 6. Electro-hydraulic actuator; 61. Servo motor; 62. Two-dimensional pump; 63. Housing; 64. Brake piston; 641. Left channel; 642. Right channel; 65. Pump piston; 651. Main body; 6511. Left transition groove; 6512. Right transition groove; 652. Pump shaft; 66. End cover; 661. Cam groove; 67. Left chamber; 68. Right chamber; 69. Forward chamber; 610. Reverse chamber; 611. Roller; 612. Coupling; 6121. Sliding groove; 613. Pulley. Detailed Implementation

[0019] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0020] like Figure 1As shown, this distributed drive-by-wire electro-hydraulic braking system includes an on-board computer 1, a brake assembly 3, a brake pedal position sensor 4, a wheel speed sensor 5, and an electro-hydraulic actuator 6. The brake pedal position sensor 4, wheel speed sensor 5, and electro-hydraulic actuator 6 are all electrically connected to the on-board computer 1, and the on-board computer 1 can control the electro-hydraulic actuator 6 to work independently.

[0021] The vehicle has four wheels 2, and four brake assemblies 3, four wheel speed sensors 5, and four electro-hydraulic actuators 6. The brake assembly 3 is installed at the wheel 2, the wheel speed sensor 5 is installed at the wheel 2 and is used to monitor the rotational speed of the wheel 2, and the electro-hydraulic actuator 6 is located in the brake assembly 3.

[0022] like Figure 2 As shown, the brake assembly 3 includes a bracket 31, a caliper 32 mounted on the bracket 31, and a pair of brake pads 33 mounted in the bracket 31. An electro-hydraulic actuator 6 is inserted and fixed in the caliper 32, and the electro-hydraulic actuator 6 can push the brake pads 33 to move.

[0023] like Figure 3 , Figure 4As shown, the electro-hydraulic actuator 6 includes a servo motor 61 and a two-dimensional pump 62. The two-dimensional pump 62 includes a housing 63, a brake piston 64 slidably disposed within the housing 63, a pump piston 65 slidably disposed within the brake piston 64, and two end caps 66 fixedly connected to the brake piston 64. Each of the two end caps 66 has a cam groove 661 on its outer side, and the two cam grooves 661 are arranged with a 90-degree phase difference. The pump piston 65 includes a main body 651 and a pump shaft 652. The main body 651 is located in... Between the two end caps 66, and between the main body 651 and the two end caps 66, are two non-communicating chambers: a left chamber 67 and a right chamber 68. The right end of the brake piston 64 has a forward chamber 69 between it and the outer casing 63, and the left end of the brake piston 64 has a backward chamber 610 between it and the outer casing 63. The brake piston 64 has a left passage 641 and a right passage 642. The main body 651 has a left transition groove 6511 and a right transition groove 6512. The left chamber 67 is connected to the left transition groove 6511 and the right passage 642. Channel 642 can communicate with the forward chamber 69. The right chamber 68 can communicate with the retraction chamber 610 through the right transition groove 6512 and the left channel 641. The two ends of the pump shaft 652 pass through two end covers 66 respectively. Rollers 611 that can slide along the cam groove 661 are respectively provided at both ends of the pump shaft 652. The servo motor 61 is fixed in the brake piston 64. A coupling 612 is provided between the output shaft of the servo motor 61 and the pump shaft 652. The coupling 612 is cylindrical. The side wall is provided with two long, narrow sliding grooves 6121 that are axially arranged along the pump shaft 652. The pump shaft 652 is provided with two pulleys 613. The pulleys 613 are embedded in the sliding grooves 6121 and can move along the sliding grooves 6121. The output shaft of the servo motor 61 can drive the pump piston 65 to rotate through the coupling 612, so that the roller 611 slides along the cam groove 661 and the brake piston 64 can partially extend out of the housing 63 after axial movement.

[0024] During braking, the output shaft of the servo motor 61 rotates, driving the pump piston 65 to rotate via the coupling 612. This causes the roller 611 to slide along the cam groove 661. The sliding of the roller 611 along the cam groove 661 moves the pump piston 65 to the left, changing the volume of the forward chamber 69, the reverse chamber 610, the left chamber 67, and the right chamber 68. This allows the oil in the left chamber 67 to flow into the forward chamber 69 through the left transition groove 6511 and the right channel 642, and allows the oil in the reverse chamber 610 to enter the right chamber 68 through the left channel 641 and the right transition groove 6512. This causes the brake piston 64 to move to the left and partially extend out of the housing 63, pushing the brake pad 33 to move. Braking is achieved; after the brake pedal is released, the output shaft of the servo motor 61 rotates in the opposite direction, driving the pump piston 65 to rotate in the opposite direction through the coupling 612, causing the roller 611 to slide in the opposite direction along the cam groove 661. The roller 611 sliding along the cam groove 661 causes the pump piston 65 to move to the right, changing the volume of the forward chamber 69, the backward chamber 610, the left chamber 67, and the right chamber 68. This causes the oil in the forward chamber 69 to flow back to the left chamber 67 through the right channel 642 and the left transition groove 6511, and causes the oil in the right chamber 68 to flow to the backward chamber 610 through the right transition groove 6512 and the left channel 641. This causes the brake piston 64 and the pump piston 65 to return to their original positions, completing one braking cycle.

[0025] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

[0026] Although this document frequently uses terms such as vehicle-mounted computer 1, wheel 2, brake assembly 3, bracket 31, caliper 32, brake pad 33, brake pedal position sensor 4, wheel speed sensor 5, electro-hydraulic actuator 6, servo motor 61, two-dimensional pump 62, housing 63, brake piston 64, left channel 641, right channel 642, pump piston 65, main body 651, left transition groove 6511, right transition groove 6512, pump shaft 652, end cover 66, cam groove 661, left chamber 67, right chamber 68, forward chamber 69, reverse chamber 610, roller 611, coupling 612, sliding groove 6121, pulley 613, etc., the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any additional limitation would contradict the spirit of this utility model.

Claims

1. A distributed drive-by-wire electro-hydraulic braking system, comprising an onboard computer (1) and a plurality of brake assemblies (3) mounted on the wheels (2), characterized in that, It also includes a brake pedal position sensor (4), several wheel speed sensors (5) installed at the wheels (2) for monitoring the rotational speed of the wheels (2), and an electro-hydraulic actuator (6) disposed in the brake assembly (3). The brake pedal position sensor (4), the wheel speed sensors (5), and the electro-hydraulic actuator (6) are all electrically connected to the on-board computer (1). The on-board computer (1) can control the electro-hydraulic actuator (6) to work independently. The electro-hydraulic actuator (6) includes a servo motor (61) and a two-dimensional pump (62). The two-dimensional pump (62) includes a housing (63) and a sliding... A brake piston (64) is installed in the housing (63). The brake piston (64) has a forward chamber (69) and a backward chamber (610) between its two ends and the housing (63). The servo motor (61) drives the two-dimensional pump (62) to draw hydraulic oil from the backward chamber (610) into the forward chamber (69) to move the brake piston (64) to apply braking force. The servo motor (61) drives the two-dimensional pump (62) to draw hydraulic oil from the forward chamber (69) into the backward chamber (610) to move the brake piston (64) to release the braking force.

2. The distributed wire-controlled electro-hydraulic braking system according to claim 1, characterized in that, The brake assembly (3) includes a bracket (31), a caliper (32) disposed on the bracket (31), and a pair of brake pads (33) disposed in the bracket (31). The electro-hydraulic actuator (6) is inserted and fixed in the caliper (32), and the electro-hydraulic actuator (6) can push the brake pads (33) to move.

3. A distributed wire-controlled electro-hydraulic braking system according to claim 1 or 2, characterized in that, The two-dimensional pump (62) further includes a pump piston (65) slidably inserted in the brake piston (64) and two end caps (66) fixed in the brake piston (64). Each of the two end caps (66) has a cam groove (661) on its outer side, and the two cam grooves (661) are arranged with a 90-degree phase difference. The pump piston (65) includes a main body (651) and a pump shaft (652). The main body (651) is located between the two end caps (66), and the main body (651) and the two end caps (66) form a non-communicating left chamber (67) and a right chamber (68). The brake piston (64) has a left channel (641) and a right channel (642). The left chamber (67) can communicate with the forward chamber (68) through the right channel (642). 9) Connected, the right chamber (68) can be connected to the rear chamber (610) through the left channel (641), the two ends of the pump shaft (652) pass through the two end caps (66) respectively, and the two ends of the pump shaft (652) are respectively provided with rollers (611) that can slide along the cam groove (661). The servo motor (61) is fixed in the brake piston (64). A coupling (612) is provided between the output shaft of the servo motor (61) and the pump shaft (652). The output shaft of the servo motor (61) can drive the pump piston (65) to rotate through the coupling (612) so that the rollers (611) slide along the cam groove (661) and the brake piston (64) can partially extend out of the outer shell (63) after axial movement.

4. A distributed wire-controlled electro-hydraulic braking system according to claim 3, characterized in that, The main body (651) has a left transition groove (6511) and a right transition groove (6512). The left chamber (67) can be connected to the right channel (642) through the left transition groove (6511), and the right chamber (68) can be connected to the left channel (641) through the right transition groove (6512).

5. A distributed wire-controlled electro-hydraulic braking system according to claim 3, characterized in that, The coupling (612) is cylindrical. The side wall of the coupling (612) is provided with a number of long, narrow sliding grooves (6121) that are axially arranged along the pump shaft (652). The pump shaft (652) is provided with a number of pulleys (613). The pulleys (613) are embedded in the sliding grooves (6121) and can move along the sliding grooves (6121).

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