EPB system on heavy commercial vehicle

Abstract

The invention relates to an EPB system on a heavy-duty commercial vehicle. The EPB system solves the problems existing in a traditional parking braking system used by the heavy-duty commercial vehicle at present. Comprising an EPB switch, an EPB controller, an ABS-ECU, a CAN bus, a wheel speed sensor, a front axle diaphragm cylinder, an ABS electromagnetic valve, a relay valve, a brake master valve, a temporary parking valve, a two-way one-way valve, a parking memory valve, a process control valve, an air pressure sensor, a driving relay valve, a parking relay valve, a spring brake cylinder, an air compressor, an air processing unit, an air cylinder and a brake pipeline. The operation process is simplified, the vehicle is more intelligent, simpler, more convenient and safer, accidents are reduced, and the comfort and safety of the whole vehicle are improved.

Description

Technical Field

[0001] The invention relates to an EPB system on a heavy-duty commercial vehicle, and belongs to the technical field of heavy-duty commercial vehicles. Background Art

[0002] The traditional parking brake system currently used in heavy commercial vehicles requires the clutch and throttle to cooperate reasonably when starting on a slope. The parking brake system adopts the traditional mechanical air brake handbrake structure, and uses the parking hand valve for manual exhaust brake and inflation release brake. The parking hand valve is a mechanical structure and requires a lot of force to operate. Frequent use of the handbrake reduces the service life of the parking spring cylinder. When the driver forgets to pull the handbrake during parking, the parking reliability is poor. The parking brake operation process and actuator of the traditional structure are complicated, which is not conducive to the driver's more convenient operation of the parking brake and creating a more comfortable driving space, and is not conducive to the safety of the vehicle. At the same time, the braking system has a slow braking response and low braking efficiency during parking braking. Summary of the invention

[0003] The present invention solves the problems existing in the conventional parking brake system currently used in heavy-duty commercial vehicles by providing an EPB system on a heavy-duty commercial vehicle.

[0004] The present invention is achieved by the following technical solutions:

[0005] An EPB system on a heavy-duty commercial vehicle includes an EPB switch 1, an EPB controller 2, an ABS-ECU 3, a CAN bus 4, a wheel speed sensor 5, a front axle diaphragm cylinder 6, an ABS solenoid valve 7, a relay valve 8, a brake master valve 9, a temporary parking valve 10, a two-way check valve 11, a parking memory valve 12, a process control valve 13, an air pressure sensor 14, a driving relay valve 15, a parking relay valve 16, a spring brake cylinder 17, an air compressor 18, an air processing unit 19, an air reservoir 20 and a brake pipeline;

[0006] The EPB switch 1, the EPB controller 2 and the CAN bus 4 are all connected to the ABS-ECU 3 through cables. The wheel speed sensor 5 is installed on the wheel and connected to the CAN bus 4 through cables. The air inlet of the front axle diaphragm cylinder 6 is connected to the air outlet of the ABS solenoid valve 7. The air inlet of the ABS solenoid valve 7 is connected to the air outlet of the relay valve 8. The air outlet of the brake master valve 9 is connected to the control port of the relay valve 8. The air outlet of the air compressor 18 is connected to the air inlet of the air processing unit 19. The port 23 of the air processing unit 19 is connected to the air reservoir 20. The one-way valve 2 of the air reservoir 20 Port 3 is connected to the air inlet of the parking memory valve 12, the air outlet of the parking memory valve 12 is connected to the air inlet of the process control valve 13, the air outlet of the process control valve 13 is connected to the air inlet of the parking relay valve 16, the air pressure sensor 14 is connected to the process control valve 13 through a cable, the air outlet of the parking relay valve 16 is connected to the air inlet of the spring brake cylinder 17, the rear axle driving air reservoir 20 is connected to the air inlets of the temporary parking valve 10 and the driving relay valve 15, the air outlet of the temporary parking valve 10 is connected to the air inlet of the two-way check valve 11, and the air outlet of the two-way check valve 11 is connected to the control port of the driving relay valve 15.

[0007] The present invention simplifies the operation process, makes the vehicle more intelligent, simple and safe, reduces the occurrence of accidents, and improves the comfort and safety of the whole vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic diagram of the gas circuit of the EPB system of the present invention, wherein: 1: EPB switch, 2: EPB controller, 3: ABS-ECU, 4: CAN bus, 5: wheel speed sensor, 6: front axle diaphragm cylinder, 7: ABS solenoid valve × 4, 8: relay valve, 9: brake master valve, 10: temporary parking valve, 11: two-way one-way valve, 12: parking memory valve, 13: process control valve, 14: air pressure sensor, 15: driving relay valve, 16: parking relay valve, 17: spring brake cylinder, 18: air compressor, 19:, air processing unit, 20: air tank. DETAILED DESCRIPTION

[0009] like Figure 1 As shown, the present invention is an EPB system for a heavy-duty commercial vehicle, comprising an EPB switch 1, an EPB controller 2, an ABS-ECU 3, a CAN bus 4, a wheel speed sensor 5, a front axle diaphragm cylinder 6, an ABS solenoid valve 7, a relay valve 8, a brake master valve 9, a temporary parking valve 10, a two-way check valve 11, a parking memory valve 12, a process control valve 13, an air pressure sensor 14, a driving relay valve 15, a parking relay valve 16, a spring brake cylinder 17, an air compressor 18, an air processing unit 19, an air reservoir 20 and a brake pipeline.

[0010] The EPB switch 1, the EPB controller 2 and the CAN bus 4 are all connected to the ABS-ECU 3 through cables. The wheel speed sensor 5 is installed on the wheel and connected to the CAN bus 4 through cables. The air inlet of the front axle diaphragm cylinder 6 is connected to the air outlet of the ABS solenoid valve 7. The air inlet of the ABS solenoid valve 7 is connected to the air outlet of the relay valve 8. The air outlet of the brake master valve 9 is connected to the control port of the relay valve 8. The air outlet of the air compressor 18 is connected to the air inlet of the air processing unit 19. The port 23 of the air processing unit 19 is connected to the air reservoir 20. The one-way valve 2 of the air reservoir 20 Port 3 is connected to the air inlet of the parking memory valve 12, the air outlet of the parking memory valve 12 is connected to the air inlet of the process control valve 13, the air outlet of the process control valve 13 is connected to the air inlet of the parking relay valve 16, the air pressure sensor 14 is connected to the process control valve 13 through a cable, the air outlet of the parking relay valve 16 is connected to the air inlet of the spring brake cylinder 17, the rear axle driving air reservoir 20 is connected to the air inlets of the temporary parking valve 10 and the driving relay valve 15, the air outlet of the temporary parking valve 10 is connected to the air inlet of the two-way check valve 11, and the air outlet of the two-way check valve 11 is connected to the control port of the driving relay valve 15.

[0011] In the present invention, in order to realize the EPB function, the original connecting gas path is retained (see gas path principle for details). Figure 1 ), add pipelines in the dotted line area shown in the figure. The specific scheme is as follows: add a parking memory valve 12 and a process control valve 13 between the third circuit air reservoir 20 and the parking relay valve 16, and install an air pressure sensor 14 to detect the air pressure in the parking brake air chamber of the spring brake cylinder 17; add an air intake pipeline between the first circuit air reservoir 20, the brake master valve 9 and the driving relay valve 15, including a temporary parking valve 10 and a two-way check valve 11.

[0012] When releasing the parking brake, push the EPB switch 1 downward, the parking indicator light goes out, the parking memory valve 12 and the process control valve 13 are opened, and the gas passes through the parking memory valve 12 and the process control valve 13 to the 4th port of the parking relay valve 16. After the 4th port of the parking relay valve 16 receives the signal, the gas from the 1st port of the parking relay valve 16 reaches the rear chamber of the spring brake cylinder 17. After the gas reaches a certain pressure, the spring is compressed. Under the action of the gas, the brake spring in the spring brake cylinder 17 is pushed back, and the parking brake is released.

[0013] When temporarily parking, turn on the temporary stop switch of EPB switch 1, the temporary stop indicator light of the switch is on, the EPB controller 2 receives the switch signal, and feeds the signal back to the temporary parking valve 10, the temporary parking valve 10 controls the driving relay valve 15 through the two-way check valve 11, after the 4th port of the driving relay valve 15 receives the signal, the gas flows from the 1st port of the driving relay valve 15 to the 2nd port and passes to the front chamber of the spring brake cylinder 17, pushing the diaphragm in the air chamber, so that the push rod in the air chamber moves forward, and applies force to the rear axle brake drum to start temporary parking.

[0014] When the temporary parking is released, the vehicle starts or the brake is released by the parking switch, the temporary parking brake will be released, and the temporary parking working indicator light will automatically stop flashing. When the vehicle starts, the 11 and 12 ports of the brake master valve 9 are closed, and the air supply from ports 21 and 22 is stopped. The compressed air in the front axle diaphragm cylinder 6 and the air pipe is discharged into the atmosphere through the exhaust port of the brake master valve 9, and the compressed air in the rear axle spring brake cylinder 17 and the air pipe is discharged into the atmosphere through the exhaust port of the driving relay valve 16. At this time, the temporary parking brake will be released.

[0015] When the vehicle is stationary and the accelerator is not pressed for 3 seconds, the system will automatically activate the temporary parking brake. If the temporary parking time exceeds 2 minutes, the system will activate the parking brake and turn off the temporary parking brake at the same time. At this time, this function is beneficial to extend the life of the parking spring cylinder. Since the temporary parking function locks the air when the foot brake is pressed, the temporary parking function can reduce the emission of parking air and save the use of air source and energy.

[0016] The EPB controller 2 shares information with other electronic control systems of the vehicle through the CAN bus 4, such as the ABS-ECU 3, to collect signal data such as the vehicle's driving speed, engine speed, torque, parking brake switch, clutch position, brake pedal, etc. At the same time, the EPB controller 2 can also collect and detect relevant vehicle information by itself, such as: transmission gear position, shift handle, brake signal, etc., to judge the driving condition of the vehicle, and then form a control logic to drive the parking memory valve 12 to control the parking brake. If the vehicle is turned off when the engine is in working state and the parking brake switch is forgotten to be pulled up, the vehicle will automatically start parking. Even if the vehicle forgets to push the parking switch to release the parking brake when the vehicle is engaged, the clutch is released, and the gas is added, the vehicle will brake to release the parking brake.

[0017] For heavy-duty vehicles, EPB can significantly improve the braking response time, shorten the braking distance, and greatly improve the safety and reliability of the vehicle's braking. The traditional mechanical handbrake valve is eliminated, which saves layout space and provides the greatest freedom for interior design. As vehicle driving safety is increasingly valued and vehicle active safety technology is improved, the safety of its braking system is particularly important. The deployment of EPB intelligent braking systems for heavy-duty commercial vehicles will be the future development direction.

[0018] The electronic control system realizes parking brake and combines parking brake with driving brake through electronic control. The design of EPB system can realize:

[0019] 1. The traditional parking hand valve is replaced by the EPB electronic switch. Pulling up the EPB switch indicates the hand brake, and pushing down the EPB switch indicates releasing the hand brake. Pulling up the EPB switch during driving will give priority to using the service brake. The parking brake will be activated only when the service brake fails or the vehicle speed is less than 7km / h.

[0020] 2. Temporary parking function. When the braking is allowed to activate the temporary parking function, there is no need to keep pressing the brake or using the handbrake when parking on a slope waiting for the traffic light. The system will automatically start the temporary parking function. When the vehicle needs to drive, you only need to lightly tap the accelerator to release the brake.

[0021] 3. In case of emergency during driving, pulling up the EPB switch can achieve emergency braking, and the vehicle will not deviate or skid.

[0022] 4. When the driver is driving, if he forgets to release the handbrake, the system will automatically release the parking brake after starting.

[0023] 5. When the car is turned off, if it is not parked, the parking brake will be automatically activated.

[0024] 6. It has a hill start assist function to prevent the vehicle from rolling back.

[0025] The present invention realizes parking brake and an electronic control system combining parking brake and driving brake by electronic control. EPB transforms the traditional mechanical handbrake into an electronic control handbrake, replaces some mechanical components with electronic components, and integrates driving brake, parking brake and other functions. The EPB system inputs signals to the controller through a key switch button, and the controller controls the mechanical valve body to perform parking brake and parking release by electronic control. At the same time, the CAN line network communicates with other controllers of the whole vehicle, realizing networking and intelligence.

Claims

1. An EPB system on a heavy commercial vehicle, characterized by: Including EPB switch, EPB controller, ABS-ECU, CAN bus, wheel speed sensor, front axle diaphragm cylinder, ABS solenoid valve, relay valve, brake master valve, temporary parking valve, two-way check valve, parking memory valve, process control valve, air pressure sensor, driving relay valve, parking relay valve, spring brake cylinder, air compressor, air handling unit, air reservoir and brake pipeline; The EPB switch, EPB controller and CAN bus are all connected to the ABS-ECU through cables. The wheel speed sensor is installed on the wheel and connected to the CAN bus through cables. The air inlet of the front axle diaphragm cylinder is connected to the air outlet of the ABS solenoid valve, the air inlet of the ABS solenoid valve is connected to the air outlet of the relay valve, the air outlet of the brake master valve is connected to the control port of the relay valve, the air outlet of the air compressor is connected to the air inlet of the air handling unit, ports 2 and 3 of the air handling unit are connected to the air reservoir, port 23 of the one-way valve of the air reservoir is connected to the air inlet of the parking memory valve, the air outlet of the parking memory valve is connected to the air inlet of the process control valve, the air outlet of the process control valve is connected to the air inlet of the parking relay valve, the air pressure sensor is connected to the process control valve through cables, the air outlet of the parking relay valve is connected to the air inlet of the spring brake cylinder, the rear axle driving air reservoir is connected to the temporary parking valve and the driving relay valve inlet, the temporary parking valve outlet is connected to the air inlet of the two-way one-way valve, and the air outlet of the two-way one-way valve is connected to the control port of the driving relay valve.

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