EPB system of heavy-duty truck and control method

Abstract

The EPB system comprises an air supply device and a brake master valve, and the brake master valve, a quick release valve, an ABS electromagnetic valve I and a front axle brake cylinder are connected in sequence; the brake main valve, the temporary stop pile-up valve and the rear axle brake cylinder are connected in sequence, and the temporary stop pile-up valve is connected with the second air cylinder; and the rear axle brake cylinder, the EPB pile-up valve and the third air reservoir are connected in sequence. The driving relay valve and the two ABS electromagnetic valves are integrated on the temporary parking integrated valve, and the EPB controller and the parking relay valve are integrated on the EPB, so that a plurality of parts such as a temporary parking valve, a two-way one-way valve, a parking memory valve and a process control valve are omitted, and the types and the number of the parts are greatly reduced. Therefore, the structure and the layout of the system are simplified, the complexity of the system is reduced, the development cycle and the purchase cost are greatly saved, and the production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of heavy truck parking brake, and particularly relates to an EPB system and a control method of a heavy truck. BACKGROUND

[0002] The traditional parking brake system mostly adopts a mechanical hand brake, which has a relatively complex structure and a large number of components, thereby increasing the manufacturing cost and affecting the operation convenience and stability of the brake effect of the vehicle to some extent. With the wide application of electronic technology in the field of automobiles, the electronic parking brake system (EPB) gradually becomes a research and application hotspot.

[0003] At present, the EPB control system usually includes an EPB switch, an EPB controller, an ABS-ECU, a wheel speed sensor, a front axle diaphragm cylinder, an ABS electromagnetic valve, a relay valve, a brake master cylinder, a temporary parking valve, a double-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 reservoir and a brake pipeline and a plurality of components. Through the cooperative work of these components, the temporary brake in driving and the long-time brake after parking can be realized to replace the traditional mechanical hand brake.

[0004] However, the existing EPB system involves a large number of components, and the integration degree of the components is low, which not only makes the structure of the system complex, increases the manufacturing and assembly difficulty, but also may cause poor cooperation between the components, thereby affecting the reliability and stability of the brake system. SUMMARY

[0005] To solve the problems in the prior art, the application aims to provide an EPB system and a control method of a heavy truck, which solve the problems of a large number of components and low integration degree of the EPB system.

[0006] To achieve the above-mentioned purpose, the technical scheme of the application is as follows: An EPB system of a heavy truck, comprising a gas supply device and a brake master cylinder, wherein the gas supply device is connected with a first air reservoir, a second air reservoir and a third air reservoir respectively, and the air inlet of the brake master cylinder is connected with the first air reservoir and the second air reservoir respectively; The air outlet one of the brake master cylinder, a quick release valve, an ABS electromagnetic valve one and a front axle brake cylinder are connected in sequence; the air outlet two of the brake master cylinder, the control port of a temporary parking integrated valve and the air inlet one of a rear axle brake cylinder are connected in sequence, the air inlet of the temporary parking integrated valve is connected with the second air reservoir; the air inlet two of the rear axle brake cylinder, an EPB integrated valve and the third air reservoir are connected in sequence; Among them, the temporary stop integrated valve includes a driving relay valve and two ABS solenoid valves 2, and the EPB integrated valve includes an EPB controller and a parking relay valve. The EPB controller is electrically connected to the EPB switch, the ABS solenoid valve 2 and the ABS-ECU respectively.

[0007] Furthermore, the control port and the air inlet of the temporary stop integrated valve correspond to the control port and the air inlet of the driving relay valve respectively, the air outlet of the driving relay valve is connected to the air inlet of the two ABS solenoid valves 2 respectively, and the air outlets of the two ABS solenoid valves 2 correspond to the air outlets of the temporary stop integrated valve respectively.

[0008] Furthermore, the air inlet and the air outlet of the EPB integrated valve correspond to the air inlet and the air outlet of the parking relay valve respectively.

[0009] Furthermore, the air supply device includes an air compressor and an air processing unit, the outlet of the air compressor is connected to the air inlet of the air processing unit, and the air outlet of the air processing unit is respectively connected to the air inlet of the first air tank, the air inlet of the second air tank and the air inlet of the third air tank.

[0010] Furthermore, a pressure sensor is provided on the pipeline between the rear axle brake cylinder and the temporary stop integrated valve, and the pressure sensor is electrically connected to the EPB controller.

[0011] Furthermore, the EPB system further includes a wheel speed sensor, which is mounted on a wheel of the heavy truck and electrically connected to the ABS-ECU.

[0012] Furthermore, the EPB system also includes a battery, which is used to supply power to the EPB system.

[0013] A control method for an EPB system of a heavy-duty truck: When the brake pedal is depressed, the gas in the first air reservoir and the second air reservoir enters the front axle brake cylinder and the rear axle brake cylinder respectively through the brake master valve to perform service braking; When the EPB controller detects that the vehicle switches from dynamic braking to static state and holds the brake for 3 seconds or the EPB switch is used to activate the temporary parking brake, the ABS-ECU controls the temporary parking integrated valve to pressurize the rear axle brake cylinder through the second air reservoir; when the pedal is released or the EPB switch is turned off, the temporary parking brake is released; When the temporary parking brake exceeds the set time or the parking brake is turned on by the EPB switch, it switches to the parking brake; when the brake pedal is pressed or the EPB switch is turned off, the gas in the third air reservoir flows into the rear axle brake cylinder through the EPB integrated valve, releasing the parking brake.

[0014] Compared with the prior art, the EPB system and control method for heavy-duty trucks of the present invention have the following advantages: By integrating the driving relay valve and two ABS solenoid valves into the temporary stop integrated valve, and the EPB controller and parking relay valve into the EPB integrated valve, this system eliminates multiple components, including the temporary stop valve, two-way check valve, parking memory valve, and process control valve. This significantly reduces the number and variety of components. This not only simplifies the system structure and layout, reducing system complexity, but also significantly shortens development cycles and procurement costs, improving production efficiency and economic benefits.

[0015] The EPB system of this invention is applicable to a variety of heavy-duty trucks and can meet the parking brake requirements of trucks of varying tonnage and usage. The high degree of component integration reduces connection points and potential failure points, improving system reliability and stability, and reducing the risk of brake failure due to component malfunction. Furthermore, the system communicates with other vehicle controllers via a CAN bus, enabling networked and intelligent control. This system can monitor and assess the vehicle's driving conditions in real time, allowing for timely adjustment of braking strategies to ensure proper operation of the braking system and enhance overall vehicle safety and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings: Figure 1 A schematic diagram of the overall structure provided by an embodiment of the present invention.

[0017] Description of reference numerals: 1. EPB switch; 2. Battery; 3. ABS-ECU; 4. Wheel speed sensor; 5. Front axle brake cylinder; 6. ABS solenoid valve 1; 7. Quick release valve; 8. Brake master valve; 9. Temporary stop integrated valve; 10. Pressure sensor; 11. EPB integrated valve; 12. Rear axle brake cylinder; 13. Air compressor; 14. Air handling unit; 151. First air reservoir; 152. Second air reservoir; 153. Third air reservoir. DETAILED DESCRIPTION

[0018] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0019] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second" and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0020] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0021] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0022] like Figure 1 As shown, an EPB system of a heavy-duty truck includes an air supply device and a brake master valve 8. The air supply device is connected to a first air reservoir 151, a second air reservoir 152, and a third air reservoir 153 respectively; the air inlet 1 and the air inlet 2 of the brake master valve 8 are connected to the first air reservoir 151 and the second air reservoir 152 respectively; The air outlet 1 of the brake master valve 8, the quick release valve 7, the ABS solenoid valve 16 and the front axle brake cylinder 5 are connected in sequence; the air outlet 2 of the brake master valve 8, the control port of the temporary stop integrated valve 9, and the air inlet 1 of the rear axle brake cylinder 12 are connected in sequence, and the air inlet of the temporary stop integrated valve 9 is connected to the second air reservoir 152; the air inlet 2 of the rear axle brake cylinder 12, the EPB integrated valve 11 and the third air reservoir 153 are connected in sequence.

[0023] In a preferred embodiment of the present invention, the temporary stop integrated valve 9 includes a driving relay valve and two ABS solenoid valves 2, the driving relay valve includes an air inlet, two air outlets, a control port and an exhaust port, and the ABS solenoid valve 2 includes an air inlet, an air outlet and an exhaust port; The control port and air inlet of the temporary stop integrated valve 9 correspond to the control port and air inlet of the driving relay valve respectively. The air outlet of the driving relay valve is connected to the air inlet of the two ABS solenoid valves 2 respectively, and the air outlets of the two ABS solenoid valves 2 correspond to the air outlets of the temporary stop integrated valve 9 respectively.

[0024] Specifically, by integrating the driving relay valve and two ABS solenoid valves 2 into the temporary stop integrated valve 9, a high degree of valve integration is achieved. This design eliminates the temporary stop valve and two-way one-way valve in the traditional system, reduces the number and types of parts, makes the entire system structure more compact, and reduces the system complexity. The integrated design of the temporary stop integrated valve 9 is conducive to shortening the air path length, reducing the transmission time and pressure loss of the gas in the pipeline, so that the system responds to the control signal more quickly. When the EPB integration 11 sends a control signal to the temporary stop integrated valve 9, the driving relay valve and the ABS solenoid valve 2 can act quickly to inflate or exhaust the front axle brake cylinder 5 in time, thereby realizing the parking brake or release operation of the vehicle.

[0025] In a preferred embodiment of the present invention, the EPB integrated valve 11 includes an EPB controller and a parking relay valve, and the air inlet and air outlet of the EPB integrated valve 11 respectively correspond to the air inlet and air outlet of the parking relay valve; the EPB controller is electrically connected to the parking relay valve, EPB switch 1, and ABS solenoid valve 2, respectively, and the EPB controller and wheel speed sensor 4 are both electrically connected to ABS-ECU3.

[0026] Specifically, the EPB controller and parking relay valve are integrated into one system, eliminating the parking memory valve and process control valve in traditional systems. The EPB integrated valve is controlled by the EPB controller. This integrated design significantly reduces the number of components, simplifies the system structure, reduces complexity, improves assembly efficiency, facilitates installation and maintenance, and reduces production costs. The EPB controller is electrically connected to EPB switch 1 and ABS solenoid valve 2. It can quickly receive switch signals and accurately control the operation of the parking relay valve, achieving a rapid parking brake response. In an emergency, for example, it quickly builds brake pressure, shortens the stopping distance, and ensures driving safety.

[0027] In a preferred embodiment of the present invention, the air supply device includes an air compressor 13 and an air processing unit 14, the outlet of the air compressor 13 is connected to the air inlet of the air processing unit 14, and the air outlet of the air processing unit 14 is respectively connected to the air inlet of the first air cylinder 151, the air inlet of the second air cylinder 152 and the air inlet of the third air cylinder 153.

[0028] Specifically, the air treatment unit 14 dries, filters and performs a series of processes on the compressed air to remove water, impurities and oil, etc. therein, effectively improving the purity and quality of the compressed air. The optimized compressed air can on the one hand prolong the service life of each pneumatic component in the brake system, reduce wear and failure caused by impurities; on the other hand, it can prevent the air path from being blocked by water vapor condensing into ice at low temperature, and ensure the stable operation of the system under various working conditions. At the same time, the air outlets of the air treatment unit are respectively connected to the air inlets of the first air reservoir 151, the second air reservoir 152 and the third air reservoir 153, realizing reasonable distribution of the air source, meeting the air demand of different parts, and improving the air supply efficiency and stability of the whole system.

[0029] In a preferred embodiment of the present application, a pressure sensor 10 is arranged on the pipeline between the rear axle brake cylinder 12 and the parking-integrated valve 9, and the pressure sensor 10 is electrically connected to the EPB controller.

[0030] Specifically, the pressure sensor 10 can monitor the air pressure in the pipeline between the rear axle brake cylinder 12 and the parking-integrated valve 9 in real time, and transmit the air pressure signal converted into an electric signal to the EPB controller. This provides accurate air pressure data for the EPB controller, enabling it to understand the pressure state of the brake system in real time and provide accurate basis for subsequent control decisions. For example, during the parking brake or temporary parking brake process, the EPB controller accurately controls the action of the parking-integrated valve 9 according to the air pressure value fed back by the pressure sensor, to ensure that the rear axle brake cylinder 12 generates appropriate braking force and realizes precise braking control.

[0031] In a preferred embodiment of the present application, the EPB system further comprises a battery for powering the EPB system.

[0032] A control method of an EPB system of a heavy truck: When the brake pedal is depressed, the gas in the first air reservoir 151 and the second air reservoir 152 enters the front axle brake cylinder 5 and the rear axle brake cylinder 12 respectively through the brake master valve 8 for driving brake; When the EPB controller detects that the vehicle is from dynamic braking to static and keeps the brake for 3s or the temporary parking is turned on through the EPB switch 1, the temporary parking brake is started, and the ABS-ECU controls the parking-integrated valve 9 to pressurize the rear axle brake cylinder 12 through the second air reservoir 152; When the pedal is released or the EPB switch 1 is turned off, the temporary parking brake is released; When the temporary parking brake exceeds the set time or the parking brake is turned on through the EPB switch 1, the parking brake is switched; when the brake pedal is depressed or the EPB switch 1 is turned off, the gas in the third air reservoir 153 flows into the rear axle brake cylinder 12 through the EPB integrated valve 11 to release the parking brake.

[0033] Working principle of EPB system of heavy-duty trucks: During service braking, the driver steps on the brake pedal, and the air inlet and outlet of the brake master valve 8 are opened. The gas enters the air inlets of the quick release valve 7 and the temporary stop integrated valve 9 respectively through the first air reservoir 151 and the second air reservoir 152 through the brake master valve 8. The gas passing through the quick release valve 7 enters the cavity of the front axle brake cylinder 5 through the ABS solenoid valve 6 to brake the front wheels; the gas passing through the temporary stop integrated valve 9 enters the front cavity of the rear axle brake cylinder 12 to brake the rear wheels.

[0034] When the vehicle is braked from dynamic to static and held for 3 seconds, the EPB system automatically activates the temporary parking brake. The EPB controller calculates the 3-second time based on the brake pedal switch signal; the EPB controller controls the activation of the temporary parking brake.

[0035] When performing temporary parking brake, press the brake pedal and hold it still for 3 seconds or turn on the temporary stop switch of EPB switch 1 to start the temporary parking brake, and the temporary stop switch indicator light of the car instrument will light up. After receiving the signal from EPB switch 1, EPB integrated valve 11 sends a CAN signal to ABS-ECU, which controls the temporary stop integrated valve 9 to pressurize. After the gas enters the control port of the temporary stop integrated valve 9 from the second air reservoir 152, it enters the front chamber of the rear axle brake cylinder 12 through the air outlet of the temporary stop integrated valve 9, pushing the diaphragm in the air chamber of the rear axle brake cylinder 12, causing the push rod in the air chamber to move forward, applying force to the rear axle brake drum, and starting the temporary parking brake. After the temporary parking brake reaches the set time, the temporary parking brake is closed and switched to the parking brake.

[0036] To release the temporary parking brake, release the brake pedal or use EPB switch 1 to release the brake. The temporary parking brake will be released and the temporary parking switch indicator light on the vehicle instrument will automatically stop flashing. When the brake pedal is released, the air inlet 1 and air inlet 2 of the brake master valve 8 are closed, and the air supply from the air outlet 1 and air outlet 2 is stopped. The compressed air in the front axle brake cylinder 5 and the corresponding air pipe is discharged into the atmosphere through the exhaust port of the brake master valve 8. The compressed air in the rear axle brake cylinder 12 and the corresponding air pipe is discharged into the atmosphere through the exhaust port of the temporary parking integrated valve 9. At this time, the temporary parking brake will be released.

[0037] When parking, the temporary parking brake reaches the set time or the EPB switch 1 is pulled up to the top to start the parking brake. The parking indicator light on the car instrument lights up, the exhaust port of the EPB integrated valve 11 opens, and the gas in the rear axle brake cylinder 12 is released to the atmosphere through the exhaust port of the EPB integrated valve 11. The spring force in the spring brake cylinder loses the air pressure to offset, pushing the brake piston to implement the parking brake.

[0038] When releasing the parking brake, step on the brake pedal and push the EPB switch 1 downwards. The parking indicator light on the vehicle instrument goes out. After the EPB integrated valve 11 receives the signal from the EPB switch 1, the gas flows from the third air reservoir 153 through the EPB integrated valve 11 into the rear chamber of the rear axle brake cylinder 12. When the gas in the rear chamber reaches a certain pressure, it compresses the brake spring in the rear axle brake cylinder 12. The brake spring is pushed back, the parking brake is released, the pedal is released, and the vehicle starts.

[0039] Emergency Braking and Release: Pulling the EPB switch 1 all the way up for more than 3 seconds activates the emergency brake. Once the emergency brake is activated, the parking brake will not automatically release when the vehicle starts. This can be achieved by pressing the EPB switch down five times within the first 10 seconds of powering on the vehicle.

[0040] Parking with the engine off: When the vehicle is turned off and the driver forgets to pull up the EPB switch 1 to park, the EPB system will automatically activate the parking brake and light up the indicator light.

[0041] Parking with door open: After the vehicle stops, if the driver forgets to pull up EPB switch 1 and does not cut off the power to park the vehicle, the EPB system will automatically activate the parking brake and the indicator light will come on after opening the main driver's door.

[0042] Low pressure release limit: When the vehicle brake pressure low pressure alarm is triggered, the parking brake will not be released automatically, and the EPB switch 1 cannot be normally operated to release the parking brake. At this time, the EPB system will maintain sufficient parking force to fix the vehicle, and the low pressure limit will be automatically cancelled after the air pressure returns to normal.

[0043] Automatic release: When the driver performs a series of operations with the intention of starting, such as closing the door, shifting gears, and stepping on the accelerator, the vehicle automatically releases the parking brake and the parking indicator light goes out.

[0044] Child lock function: Pushing the EPB switch without pressing the foot brake will not release the parking brake, preventing accidents caused by unintentional release of the parking brake.

[0045] Trailer mode: When the EPB system is in the released parking state, press the EPB switch until the vehicle is shut down for more than 5 seconds before releasing the EPB switch. The vehicle will remain in the unparked state before the shutdown.

[0046] Temporary Parking Function: When the vehicle comes to a complete stop and the footbrake is applied for 3 seconds, the EPB system automatically locks the vehicle and illuminates the temporary parking indicator. This eliminates the need to hold down the brakes or use the parking brake when waiting for traffic lights or parking on slopes. The system automatically activates the temporary parking function, allowing you to release the brakes with a simple tap of the accelerator when the vehicle needs to move.

[0047] Hill start assist: When parking / temporarily stopping on a slope, the EPB system can automatically release the parking / temporary parking brake based on the driver's actions such as closing the door, shifting gears, and pressing the accelerator, and the parking indicator light will go out when the system detects that the vehicle's power meets the starting requirements.

[0048] Sleep and wake-up function: 30 seconds after the vehicle is turned off, the EPB system enters sleep mode (low power consumption). The EPB system can be woken up by pulling up the EPB switch. In addition, the system also monitors the air pressure in the parking pipe. If pressure is detected in the pipe, it will wake up immediately for timely exhaust.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An EPB system for a heavy-duty truck, comprising an air supply device and a brake master valve, wherein the air supply device is connected to a first air reservoir, a second air reservoir, and a third air reservoir, respectively, and an air inlet of the brake master valve is connected to the first air reservoir and the second air reservoir, respectively, characterized in that: The air outlet 1 of the brake master valve, the quick release valve, the ABS solenoid valve 1 and the front axle brake cylinder are connected in sequence; the air outlet 2 of the brake master valve, the control port of the temporary stop integrated valve, and the air inlet 1 of the rear axle brake cylinder are connected in sequence, and the air inlet of the temporary stop integrated valve is connected to the second air reservoir; the air inlet 2 of the rear axle brake cylinder, the EPB integrated valve and the third air reservoir are connected in sequence; The temporary stop integrated valve includes a driving relay valve and two ABS solenoid valves 2, and the EPB integrated valve includes an EPB controller and a parking relay valve. The EPB controller is electrically connected to the EPB switch, the ABS solenoid valve 2 and the ABS-ECU respectively.

2. The EPB system for heavy trucks according to claim 1, characterized in that: The control port and air inlet of the temporary stop integrated valve correspond to the control port and air inlet of the driving relay valve respectively. The air outlet of the driving relay valve is connected to the air inlet of the two ABS solenoid valves 2 respectively. The air outlets of the two ABS solenoid valves 2 correspond to the air outlets of the temporary stop integrated valve respectively.

3. The EPB system for a heavy truck according to claim 1, characterized in that: The air inlet and the air outlet of the EPB integrated valve correspond to the air inlet and the air outlet of the parking relay valve respectively.

4. The EPB system for a heavy truck according to claim 1, characterized in that: The air supply device includes an air compressor and an air processing unit, the outlet of the air compressor is connected to the air inlet of the air processing unit, and the air outlet of the air processing unit is connected to the air inlet of the first air reservoir, the air inlet of the second air reservoir and the air inlet of the third air reservoir respectively.

5. The EPB system for a heavy truck according to claim 1, characterized in that: A pressure sensor is provided on the pipeline between the rear axle brake cylinder and the temporary stop integrated valve, and the pressure sensor is electrically connected to the EPB controller.

6. The EPB system for a heavy truck according to claim 1, characterized in that: The EPB system further includes a wheel speed sensor, which is mounted on a wheel of the heavy truck and is electrically connected to the ABS-ECU.

7. The EPB system for a heavy truck according to claim 1, characterized in that: The EPB system further includes a battery, which is used to power the EPB system.

8. A method for controlling an EPB system of a heavy-duty truck, characterized in that: Utilize the system described in any one of claims 1 to 7, and perform the following steps: When the brake pedal is depressed, the gas in the first air reservoir and the second air reservoir enters the front axle brake cylinder and the rear axle brake cylinder respectively through the brake master valve to perform service braking; When the EPB controller detects that the vehicle switches from dynamic braking to static state and holds the brake for 3 seconds or the EPB switch is used to activate the temporary parking brake, the ABS-ECU controls the temporary parking integrated valve to pressurize the rear axle brake cylinder through the second air reservoir; when the pedal is released or the EPB switch is turned off, the temporary parking brake is released; When the temporary parking brake exceeds the set time or the parking brake is turned on by the EPB switch, it switches to the parking brake; when the brake pedal is pressed or the EPB switch is turned off, the gas in the third air reservoir flows into the rear axle brake cylinder through the EPB integrated valve, releasing the parking brake.

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