Hydraulic braking system and method with linear pedal feedback sense

Abstract

The invention relates to a hydraulic braking system and method with a linear pedal feedback sense, and belongs to the field of automobile drive-by-wire hydraulic braking systems. The controller assembly is electrically connected with the hydraulic pump assembly, the hydraulic sensor and the displacement sensor, the displacement sensor obtains the stroke of the plunger rod, the hydraulic sensor monitors and feeds back hydraulic pressure in the cavity in real time, and the hydraulic pump assembly provides corresponding assisting hydraulic pressure for the mechanical execution structure. The device has the advantages that the structure is novel, hydraulic driving is used, bad factors such as friction, noise and short service life brought by a traditional transmission mechanism are avoided, a fault degradation mode is entered under the condition that a power assisting function fails, mechanical backup still exists, a driver steps on a plunger rod of a pedal to push a piston of a brake master cylinder to build pressure by pushing a feedback disc and a third piston to advance, and the brake master cylinder works normally. A better driving feeling can be provided for a driver, and the pedal feeling is smooth in the braking process.

Description

Technical Field

[0001] The present invention belongs to the field of automobile wire-controlled hydraulic brake systems, and in particular relates to a hydraulic brake system and method with linear pedal feedback. Background Art

[0002] Traditional hydraulic braking systems rely primarily on mechanical connections and hydraulic actuation, directly transmitting the driver's braking intent via a mechanical lever between the brake pedal and the master brake cylinder. However, as automotive technology evolves toward electronic and intelligent technologies, this approach has gradually revealed its limitations. The emergence of drive-by-wire hydraulic brake systems is primarily intended to better adapt to autonomous driving technology and the vehicle's electronic control functions. In autonomous driving scenarios, the vehicle must be able to accurately and quickly control braking based on electronic signals, a requirement that traditional mechanical hydraulic brake systems struggle to meet. At the same time, this system can also integrate with the vehicle's other electronic safety systems to enhance the vehicle's overall safety performance.

[0003] Drive-by-wire hydraulic brake systems, a major market trend, have gained widespread recognition for their high integration and rapid response. While these systems are complex and diverse in form and structure, they can quickly respond to braking commands in emergencies, precisely controlling braking force to ensure driving safety. Drive-by-wire hydraulic brake systems offer drivers a more linear braking feel, allowing for precise tuning of the relationship between pedal force and braking force. This gentle, stable braking process reduces driver fatigue during frequent braking. Summary of the Invention

[0004] The present invention provides a hydraulic brake system and method with linear pedal feedback to solve the problems of friction, noise, short service life and the like caused by traditional transmission mechanisms.

[0005] The technical solution adopted by the present invention is to include a controller assembly, a hydraulic pump assembly, a hydraulic sensor, a displacement sensor and a mechanical actuator, wherein the controller assembly is electrically connected to the hydraulic pump assembly, the hydraulic sensor and the displacement sensor respectively, the displacement sensor obtains the stroke of the plunger rod, the hydraulic sensor monitors and feeds back the hydraulic pressure inside the cavity in real time, and the hydraulic pump assembly provides corresponding power-assisting hydraulic pressure for the mechanical actuator structure.

[0006] The mechanical execution structure includes a longitudinally arranged brake master cylinder, a rubber feedback disk, a third piston, a plunger rod, a plunger seat, a return spring, a pedal push rod and an outer shell. The large cylindrical end of the pressure-building push rod in the brake master cylinder is seated on the rubber feedback disk and is arranged together at the front end of the third piston. The bottom of the rubber feedback disk is connected to the plunger rod, and a certain gap is reserved for adjusting the pedal feel. The rear end of the plunger rod is connected to the plunger seat, and the return spring is installed on the plunger seat. The bottom of the plunger seat is riveted to the pedal push rod.

[0007] The brake master cylinder is an independent double-chamber, with a first pressure-building piston and a second pressure-building piston arranged inside. The brake master cylinder contains brake fluid. The small cylindrical end of the pressure-building push rod extends into the first piston, and the large cylindrical end sits on the rubber feedback plate. The second return spring is sleeved on the outside of the first pressure-building piston and is located on the return spring seat.

[0008] The side wall of the outer shell is provided with a flow channel hole, which is connected to a hydraulic pressure sensor to monitor and feedback the hydraulic pressure inside the cavity in real time.

[0009] The boss of the plunger rod is located in the outer shell and is used to push the third piston forward. When the return spring is compressed, it generates tension to limit the plunger rod. The plunger seat and the ball end of the pedal push rod are riveted together at three points.

[0010] A cylindrical hole 1 is reserved at the center of the third piston, a cylindrical hole 2 is reserved at the front end for arranging a rubber feedback disk, and a V-shaped leather cup groove is reserved at the rear end.

[0011] The brake master cylinder and the outer shell are sealed with an O-ring; the third piston and the outer shell are sealed with a V-shaped leather cup 1; the third piston and the plunger rod are sealed with a V-shaped leather cup 2; and the plunger rod and the outer shell are sealed with a V-shaped leather cup.

[0012] A hydraulic braking method with linear pedal feedback includes the following two processes: (1) During the normal braking process, the brake assist is generated by the hydraulic pump assembly. After the brake pedal is stepped on, the thrust causes the plunger rod to move forward. The displacement sensor arranged on the plunger rod allows the hydraulic pump assembly to obtain a displacement signal. The driver's braking demand is calculated and the demand instruction is sent to the hydraulic pump assembly to output the corresponding assist hydraulic pressure, pushing the third piston and finally pushing the piston in the brake master cylinder to build pressure for braking. At the same time, the plunger rod moves forward and compresses the rubber feedback disc to obtain a brake feedback foot feel. By setting a reserved gap L, a good linear pedal feedback feel is achieved and the conventional brake pedal decoupling function is realized. The return spring 2 and the return spring 1 are both responsible for pushing the third piston and the plunger rod back to their original positions, so that the system is reset. (2) When the system enters the mechanical backup braking process, after the driver steps on the brake pedal, the thrust causes the plunger rod to move forward and compress the rubber feedback disc for a certain distance, directly eliminating the backup gap L3. At this time, the boss on the plunger rod begins to push the third piston forward, and finally pushes the piston in the brake master cylinder to build pressure and brake. The return spring 2 and the return spring 1 are responsible for pushing the third piston and plunger rod back to their original positions, so that the system is reset.

[0013] In the step (1), the hydraulic pressure sensor arranged on the flow channel hole on the side wall of the outer shell monitors and feeds back the hydraulic pressure inside the cavity in real time, and feeds back the hydraulic pressure to the controller assembly in time for verification with the theoretically calculated hydraulic pressure to obtain more accurate control hydraulic compensation. At the same time, the state of the hydraulic pressure inside the cavity is monitored, and the fault mode is monitored in real time to ensure that the control process is more accurate and reliable.

[0014] In the step (1), the reserved gap L must meet the condition that L= L1+L2+L3, wherein L1 is the feedback gap, L2 is the jump gap, and L3 is the backup gap. L is greater than the sum of L1+L2, so as to achieve a good linear pedal feedback feeling and realize the conventional brake pedal decoupling function. The relationship between L, L1, and L2 and the control strategy are matched according to different requirements to complete the linear pedal feedback.

[0015] The advantages of the present invention are novel structure and the use of hydraulic drive, which avoids the adverse factors such as friction, noise, and low life brought by traditional transmission mechanisms. When the power assist function fails, it enters the fault degradation mode, and there is still a mechanical backup. The driver steps on the pedal and the plunger rod directly pushes the brake master cylinder piston to build pressure by pushing the feedback plate and the third piston forward, so that the vehicle stops safely. The present invention can provide the driver with a better driving feel, and the relationship between the pedal force and the braking force can be finely adjusted and controlled. It also has the advantage of low cost. At the same time, it can realize pedal decoupling in terms of function to meet the needs of brake energy recovery, and the pedal feel is smooth during braking. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 This is an enlarged view of the initial state of the pedal feedback mechanical structure of part A of the present invention; Figure 3 This is an enlarged view of the conventional braking state of the pedal feedback mechanical structure of part A of the present invention; Figure 4 is an axial view of the pedal feedback structure of the present invention; Figure 5 It is an axial view of the third piston of the present invention. DETAILED DESCRIPTION

[0017] like Figure 1As shown, it includes a controller assembly 2 that coordinates the operation of the entire system, a hydraulic pump assembly 3 that executes hydraulic output, a hydraulic sensor 4 that monitors system dynamics, a displacement sensor 5, and a mechanical actuator 1 that is responsible for pedal force feedback and pushing the brake master cylinder to generate brake hydraulic pressure. The controller assembly 2 is electrically connected to the hydraulic pump assembly 3, the hydraulic sensor 4, and the displacement sensor 5 respectively. The displacement sensor 5 obtains the stroke of the plunger rod 104. The hydraulic sensor 4 monitors and feeds back the hydraulic pressure inside the cavity 109 in real time. The hydraulic pump assembly 3 provides corresponding power-assisting hydraulic pressure for the mechanical actuator structure 1.

[0018] like Figure 1 As shown, the mechanical execution structure 1 includes a longitudinally arranged brake master cylinder 101, a rubber feedback disk 102, a third piston 103, a plunger rod 104, a plunger seat 105, a return spring 106, a pedal push rod 107 and an outer shell 108. The large cylindrical end of the pressure-building push rod 10103 in the brake master cylinder 101 is seated on the rubber feedback disk 102 and is arranged together at the front end of the third piston 103. The bottom of the rubber feedback disk 102 is connected to the plunger rod 104, and a certain gap is reserved for adjusting the pedal feel. The rear end of the plunger rod 104 is connected to the plunger seat 105, and the return spring 106 is installed on the plunger seat 105. The bottom of the plunger seat 105 is riveted to the pedal push rod 107; the controller assembly 2 obtains the plunger rod 104 stroke returned by the displacement sensor 4 in real time, calculates the driver's demand, and sends a braking signal to the hydraulic pump assembly 3 to output the power-assisted hydraulic pressure, pushing the third piston 103 forward, and finally pushing the piston in the brake master cylinder to build pressure and brake.

[0019] like Figure 1 、 2 As shown, the brake master cylinder 101 is an independent double-chamber, with a first pressure-building piston 10101 and a second pressure-building piston 10102 arranged inside. The brake master cylinder 101 contains brake fluid. During braking, the first pressure-building piston 10101 and the second pressure-building piston 10102 push the brake fluid to the wheel cylinder to generate braking force to brake the wheel; the small cylindrical end of the pressure-building push rod 10103 extends into the first piston 10101, and the large cylindrical end sits on the rubber feedback disk 102. The second return spring 10104 is sleeved on the outside of the first pressure-building piston 10101 and is located on the return spring seat 10105.

[0020] like Figure 2 、 3 As shown, the side wall of the outer shell 108 has a flow channel hole 10801, which is connected to the hydraulic sensor 4 to monitor and feedback the hydraulic pressure inside the cavity 109 in real time, and timely feedback to the controller assembly 2 for verification with the theoretically calculated hydraulic pressure to obtain more accurate control hydraulic compensation. At the same time, it monitors the status of the hydraulic pressure inside the cavity 109 and monitors the fault mode in real time to ensure that the control process is more accurate and reliable.

[0021] like Figure 4 As shown, the boss 10401 of the plunger rod 104 is located in the outer shell 108, which is used to push the third piston 103 forward, and finally push the piston in the brake master cylinder 101 to build pressure and brake; the return spring 106 is compressed to generate tension to limit the plunger rod 104, and the plunger seat 105 and the ball head end of the pedal push rod 107 are riveted together at three points, so that the pedal push rod 107 can obtain a certain swing angle.

[0022] like Figure 5 As shown, a cylindrical hole 10301 is reserved in the center of the third piston 103, a cylindrical hole 10302 is reserved at the front end for arranging the rubber feedback disk 102, and a V-shaped leather cup groove 10303 is reserved at the rear end.

[0023] The brake master cylinder 101 of the mechanical actuator structure 1 is sealed with an O-ring 110 and the outer shell 108; the third piston 103 of the mechanical actuator structure 1 is sealed with a V-shaped leather cup 111; the third piston 103 of the mechanical actuator structure 1 is sealed with a V-shaped leather cup 2 112 and the plunger rod 104; the plunger rod 104 of the mechanical actuator structure 1 is sealed with a V-shaped leather cup 113.

[0024] How it works Under normal braking conditions, when the driver steps on the brake pedal, displacement sensor 5 detects the change in plunger rod position and outputs a signal to controller assembly 2. After calculation, the controller directly outputs a signal to hydraulic pump assembly 3, which provides power assist. This outputs hydraulic pressure to build pressure in the master brake cylinder, braking the vehicle. Simultaneously, hydraulic sensor 4, located in the fluid flow pipeline, monitors the fluid pressure and feeds it back to controller assembly 2, forming a closed-loop control loop. This precisely controls the pressure buildup rate and identifies the driver's intent to meet braking requirements. If the power assist function fails, the system enters a fault-degraded mode, but a mechanical backup still exists. When the driver steps on the pedal, the plunger rod directly pushes the feedback plate and the third piston forward, pushing the master brake cylinder piston to build pressure, bringing the vehicle to a safe stop.

[0025] A hydraulic braking method with linear pedal feedback includes the following two processes: (1) During the normal braking process, the brake assist is generated by the hydraulic pump assembly 3. After the driver steps on the brake pedal 107, the thrust causes the plunger rod 104 to move forward. The displacement sensor 5 arranged on the plunger rod 104 allows the hydraulic pump assembly 3 to obtain a displacement signal. The driver's braking demand is calculated and a demand instruction is sent to the hydraulic pump assembly 3 to output the corresponding assist hydraulic pressure, pushing the third piston 103 and finally pushing the piston in the brake master cylinder to build pressure for braking. At the same time, the plunger rod 104 moves forward and compresses the rubber feedback disc 102 to obtain a brake feedback foot feel. By setting a reserved gap L, a good linear pedal feedback feel is achieved and the conventional brake pedal decoupling function is realized. The return spring 2 10104 and the return spring 1 106 are both responsible for pushing the third piston 103 and the plunger rod 104 back to their original positions, so that the system is reset. (2) When the system enters the mechanical backup braking process, after the driver steps on the brake pedal 107, the thrust causes the plunger rod 104 to move forward and compress the rubber feedback plate 102 for a distance, directly eliminating the backup gap L3. At this time, the boss 10401 on the plunger rod 104 begins to push the third piston 103 forward, and finally pushes the piston in the brake master cylinder to build pressure braking. The return spring 2 10104 and the return spring 1 106 are both responsible for pushing the third piston 103 and the plunger rod 104 back to their original positions, so that the system is reset.

[0026] In the step (1), the hydraulic sensor 4 arranged on the flow channel hole 10801 on the side wall of the outer shell 108 monitors and feeds back the hydraulic pressure inside the cavity 109 in real time, and feeds back the hydraulic pressure to the controller assembly 2 in time for verification with the theoretically calculated hydraulic pressure to obtain more accurate control hydraulic compensation. At the same time, the state of the hydraulic pressure inside the cavity 109 is monitored, and the fault mode is monitored in real time to ensure that the control process is more accurate and reliable.

[0027] In step (1), the reserved gap L must meet the condition that L = L1 + L2 + L3, where L1 is the feedback gap, L2 is the jump gap, and L3 is the backup gap. L is greater than the sum of L1 + L2 to achieve a good linear pedal feedback feeling and realize the conventional brake pedal decoupling function. The relationship between L, L1, and L2 and the control strategy are matched according to different requirements to complete the linear pedal feedback. See Figure 2 and Figure 3 .

Claims

1. A hydraulic brake system with linear pedal feedback, characterized in that: It includes a controller assembly, a hydraulic pump assembly, a hydraulic sensor, a displacement sensor and a mechanical actuator. The controller assembly is electrically connected to the hydraulic pump assembly, the hydraulic sensor and the displacement sensor respectively. The displacement sensor obtains the stroke of the plunger rod. The hydraulic sensor monitors and feeds back the hydraulic pressure inside the cavity in real time. The hydraulic pump assembly provides the corresponding power-assisting hydraulic pressure for the mechanical actuator structure.

2. The hydraulic brake system with linear pedal feedback according to claim 1, characterized in that: The mechanical execution structure includes a longitudinally arranged brake master cylinder, a rubber feedback disk, a third piston, a plunger rod, a plunger seat, a return spring, a pedal push rod and an outer shell. The large cylindrical end of the pressure-building push rod in the brake master cylinder is seated on the rubber feedback disk and is arranged together at the front end of the third piston. The bottom of the rubber feedback disk is connected to the plunger rod, and a certain gap is reserved for adjusting the pedal feel. The rear end of the plunger rod is connected to the plunger seat, and the return spring is installed on the plunger seat. The bottom of the plunger seat is riveted to the pedal push rod.

3. The hydraulic brake system with linear pedal feedback according to claim 2, characterized in that: The brake master cylinder is an independent double-chamber, with a first pressure-building piston and a second pressure-building piston arranged inside. The brake master cylinder contains brake fluid. The small cylindrical end of the pressure-building push rod extends into the first piston, and the large cylindrical end sits on the rubber feedback plate. The second return spring is sleeved on the outside of the first pressure-building piston and is located on the return spring seat.

4. The hydraulic brake system with linear pedal feedback according to claim 2, characterized in that: The side wall of the outer shell is provided with a flow channel hole, which is connected to a hydraulic pressure sensor to monitor and feedback the hydraulic pressure inside the cavity in real time.

5. The hydraulic brake system with linear pedal feedback according to claim 2, characterized in that: The boss of the plunger rod is located in the outer shell and is used to push the third piston forward. When the return spring is compressed, it generates tension to limit the plunger rod. The plunger seat and the ball end of the pedal push rod are riveted together at three points.

6. The hydraulic brake system with linear pedal feedback according to claim 2, characterized in that: A cylindrical hole 1 is reserved at the center of the third piston, a cylindrical hole 2 is reserved at the front end for arranging a rubber feedback disk, and a V-shaped leather cup groove is reserved at the rear end.

7. The hydraulic brake system with linear pedal feedback according to claim 2, characterized in that: The brake master cylinder and the outer shell are sealed with an O-ring; the third piston and the outer shell are sealed with a V-shaped leather cup 1; the third piston and the plunger rod are sealed with a V-shaped leather cup 2; and the plunger rod and the outer shell are sealed with a V-shaped leather cup.

8. A method for using a hydraulic brake system with linear pedal feedback as claimed in any one of claims 1 to 7, characterized in that: It includes the following two processes: (1) During the normal braking process, the brake assist is generated by the hydraulic pump assembly. After the brake pedal is stepped on, the thrust causes the plunger rod to move forward. The displacement sensor arranged on the plunger rod allows the hydraulic pump assembly to obtain a displacement signal. The driver's braking demand is calculated and the demand instruction is sent to the hydraulic pump assembly to output the corresponding assist hydraulic pressure, pushing the third piston and finally pushing the piston in the brake master cylinder to build pressure for braking. At the same time, the plunger rod moves forward and compresses the rubber feedback disc to obtain a brake feedback foot feel. By setting a reserved gap L, a good linear pedal feedback feel is achieved and the conventional brake pedal decoupling function is realized. The return spring 2 and the return spring 1 are both responsible for pushing the third piston and the plunger rod back to their original positions, so that the system is reset. (2) When the system enters the mechanical backup braking process, after the driver steps on the brake pedal, the thrust causes the plunger rod to move forward and compress the rubber feedback disc for a certain distance, directly eliminating the backup gap L3. At this time, the boss on the plunger rod begins to push the third piston forward, and finally pushes the piston in the brake master cylinder to build pressure and brake. The return spring 2 and the return spring 1 are responsible for pushing the third piston and plunger rod back to their original positions, so that the system is reset.

9. The hydraulic braking method with linear pedal feedback according to claim 8, characterized in that: In the step (1), the hydraulic pressure sensor arranged on the flow channel hole on the side wall of the outer shell monitors and feeds back the hydraulic pressure inside the cavity in real time, and feeds back the hydraulic pressure to the controller assembly in time for verification with the theoretically calculated hydraulic pressure to obtain more accurate control hydraulic compensation. At the same time, the state of the hydraulic pressure inside the cavity is monitored, and the fault mode is monitored in real time to ensure that the control process is more accurate and reliable.

10. The hydraulic braking method with linear pedal feedback according to claim 8, characterized in that: In the step (1), the reserved gap L must meet the condition that L= L1+L2+L3, wherein L1 is the feedback gap, L2 is the jump gap, and L3 is the backup gap. L is greater than the sum of L1+L2, so as to achieve a good linear pedal feedback feeling and realize the conventional brake pedal decoupling function. The relationship between L, L1, and L2 and the control strategy are matched according to different requirements to complete the linear pedal feedback.

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