Drive-by-wire air brake system of extra-heavy special off-road vehicle

Abstract

The utility model discloses a drive-by-wire air brake system of an extra-heavy special off-road vehicle, which comprises an air compressor, a condenser, an air dryer, a four-loop protection valve, an automobile electric control unit, a brake valve, an air reservoir, a brake air chamber and a hand brake valve, air inlets of the brake valve and the proportional relay valves are connected with the air storage cylinder, the brake valve and a front axle and a rear axle of a vehicle are respectively provided with a group of proportional relay valves, air pressure sensors are integrated at air outlets of the proportional relay valves, and the brake valve, the proportional relay valves and the air pressure sensors are all electrically connected with the vehicle electric control unit. A differential relay valve is arranged on a connecting air path of the hand brake valve and the brake air chamber used for parking, air inlets of the hand brake valve and the differential relay valve are both connected with an air storage cylinder, a low-air-pressure alarm switch is integrated on an air outlet of the differential relay valve, and the hand brake valve is provided with an electromagnetic valve in parallel.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of automobile brake, especially a super heavy special off -road vehicle line control pneumatic brake system. BACKGROUND

[0002] The brake system is an important component of the vehicle, and is related to the safety of vehicle operation. The ordinary heavy vehicle pneumatic brake system is generally composed of an air compressor, a condenser, an air treatment unit, a brake valve, a relay valve, a differential relay valve, an air cylinder and the like. The distance from the brake valve of the ordinary heavy vehicle to the farthest brake chamber is short, and the brake reaction time has limited influence on the brake effect. However, the super heavy special off-road vehicle has large tonnage, many axles and long overall length. If the brake system is not reasonably designed, the brake reaction time will be too long, which will seriously affect the overall brake effect of the vehicle and further affect the driving safety. The overall length of the super heavy special off-road vehicle is long, the number of axles is large, and the pipeline of the brake air pressure circuit is very long, which causes the brake reaction time to be prolonged, and finally leads to the increase of the overall brake distance of the vehicle and the increase of the driving safety risk.

[0003] At the same time, in order to realize the unmanned driving function, the vehicle equipped with the pneumatic brake system needs to be configured with an EBS system. The system is provided by the supplier in a complete set, and the development cost and debugging cost are high. For the development of chassis or small batch chassis, the development cost is high, and the development cost cannot be effectively reduced. CONTENT OF THE UTILITY MODEL

[0004] In view of the above technical problems, the utility model provides a super heavy special off-road vehicle line control pneumatic brake system. The line control pneumatic brake system solves the problem of long brake reaction time caused by long overall length and many axles in the prior art, and also solves the problem of realizing the conventional brake during manned driving and the driving brake function during unmanned automatic driving at low cost. The redundancy design increases the reliability of vehicle braking.

[0005] A super heavy special off-road vehicle line control pneumatic brake system, an air compressor, a condenser, an air dryer, a four-loop protection valve, an automobile electronic control unit, a brake valve, an air cylinder, a brake chamber and a hand brake valve are provided. A proportional relay valve is arranged on the connecting air path of the brake valve and the brake chamber. The air inlet of the brake valve and the proportional relay valve is connected with the air cylinder. The air outlet of each group of proportional relay valves of the brake valve and the front and rear axles of the vehicle is integrated with an air pressure sensor. The brake valve, the proportional relay valve and the air pressure sensor are electrically connected with the automobile electronic control unit. A differential relay valve is arranged on the connecting air path of the hand brake valve and the brake chamber for parking. The air inlets of the hand brake valve and the differential relay valve are connected with the air cylinder. A low air pressure alarm switch is integrated with the air outlet of the differential relay valve. The hand brake valve is installed in parallel with an electromagnetic valve.

[0006] As the preferred technical scheme, the brake valve is provided with two air control circuits, and the brake chambers and proportional relay valves are correspondingly provided with five groups, the first two groups of brake chambers are used for front axle of the vehicle, and the corresponding two groups of proportional relay valves are controlled by one air control circuit, and the last two groups of brake chambers are used for rear axle of the vehicle, and the corresponding three groups of proportional relay valves are controlled by another air control circuit.

[0007] As the preferred technical scheme, the air cylinder is provided with four groups, wherein two groups of air cylinders are connected to the air control circuits of the proportional relay valves of the front and rear axles of the vehicle, respectively, and are used for adjusting the air pressures of the brake chambers of the front and rear axles of the vehicle, the third group is used for parking circuit, and the fourth group is used for auxiliary braking.

[0008] As the preferred technical scheme, each air cylinder is provided with a drain valve.

[0009] As the preferred technical scheme, the brake valve is a double-cavity tandem brake valve.

[0010] The beneficial effects of the utility model lie in that:

[0011] 1. The utility model realizes the brake-by-wire air pressure brake system of the five-axle and more axle super heavy special off-road vehicle, and the scheme can realize the manned driving and unmanned driving brake function of the chassis.

[0012] 2. After the brake-by-wire control system fails, the driver can still realize the service brake of the wheel brake by operating the emergency brake valve.

[0013] 3. When manned, the air circuit control of the traditional mechanical chassis is still retained, the change of the traditional mechanical chassis is small, and the air circuit system is almost unchanged.

[0014] 4. The utility model saves the cost compared with the existing EBS system, and can realize the unmanned function of the chassis.

[0015] 5. The proportional relay valve is provided with a gas pressure sensor, which is used for feeding back the gas pressure output of the proportional relay valve to the automobile electronic control unit, and the automobile electronic control unit can fine tune according to the feedback result, and improve the accuracy of the gas pressure output of the proportional relay valve according to the braking force demand of the whole vehicle.

[0016] 6. The utility model is provided with the redundancy design of the service brake system air control and wire control, and the reliability is improved. DRAWINGS

[0017] Figure 1 It is the principle diagram of the utility model.

[0018] The reference signs are as follows: 1-air compressor, 2-condenser, 3-air dryer, 4-four-loop protection valve, 5-automobile electric control unit, 6-brake valve, 7-hand brake valve, 8-differential relay valve, 9-low air pressure alarm switch, 10-solenoid valve, 11-brake chamber one, 12-brake chamber two, 13-brake chamber three, 14-brake chamber four, 15-brake chamber five, 16-proportional relay valve one, 17-proportional relay valve two, 18-proportional relay valve three, 19-proportional relay valve four, 20-proportional relay valve five, 21-air pressure sensor one, 22-air pressure sensor two, 23-air pressure sensor three, 24-air pressure sensor four, 25-air cylinder one, 26-air cylinder two, 27-air cylinder three, 28-air cylinder four. DETAILED DESCRIPTION

[0019] The technical scheme of the utility model will be described clearly and completely in combination with the drawings of the utility model. All other embodiments obtained by the person skilled in the art without making creative labor based on the embodiments of the utility model belong to the protection scope of the utility model.

[0020] As Figure 1 shown in a kind of super heavy special off-road vehicle line control air pressure brake system, air compressor 1, condenser 2, air dryer 3, four-loop protection valve 4, automobile electric control unit 5, brake valve 6, air cylinder, brake chamber, hand brake valve 7, the brake valve is equipped with proportional relay valve on the connecting gas path of brake chamber, the air inlet of brake valve and proportional relay valve is connected with air cylinder, brake valve and the air outlet of each group proportional relay valve integrated with air pressure sensor in front and rear axle of vehicle, brake valve 6, proportional relay valve and air pressure sensor are electrically connected with automobile electric control unit 5, hand brake valve 7 is equipped with differential relay valve 8 on the connecting gas path of brake chamber for parking, the air inlet of hand brake valve 7 and differential relay valve 8 is connected with air cylinder, the air outlet of differential relay valve 8 is integrated with low air pressure alarm switch 9, solenoid valve is installed in parallel with hand brake valve 7.

[0021] In the embodiment, the brake valve 6 is provided with two air control circuits, and the brake chamber 6 and the proportional relay valve are correspondingly provided with five groups. The first two groups of brake chambers are used for the front axle of the vehicle, and are respectively brake chamber one 11 and brake chamber two 12. The corresponding two groups of proportional relay valves are controlled by one air control circuit, and are respectively proportional relay valve one 16 and proportional relay valve two 17. The last two groups of brake chambers are used for the rear axle of the vehicle, and are respectively brake chamber three 13, brake chamber four 14 and brake chamber five 15. The corresponding three groups of proportional relay valves are controlled by another air control circuit, and are respectively proportional relay valve three 18, proportional relay valve four 19 and proportional relay valve five 20. The air pressure sensors provided at the two gas outlets of the brake valve 6 are respectively air pressure sensor one 21 and air pressure sensor two 22. The air outlet of the proportional relay valve one 16 is provided with air pressure sensor three 23, and the air outlet of the proportional relay valve three 18 is provided with air pressure sensor four 214.

[0022] In the embodiment, the air cylinders are provided with four groups, which are respectively air cylinder one 25, air cylinder two 26, air cylinder three 27 and air cylinder four 28. The air cylinder one 25 and the air cylinder two 26 are respectively connected to the air control circuits of the proportional relay valves of the front and rear axles of the vehicle, and are respectively used for adjusting the brake chamber air pressure of the front and rear axles of the vehicle. The air cylinder three 27 is used for the parking circuit, and the air cylinder four 28 is used for auxiliary braking.

[0023] In the embodiment, the air cylinder is provided with a drain valve.

[0024] In the embodiment, the brake valve 6 is a double-cavity tandem brake valve.

[0025] In the embodiment, the brake valve 6 is a double-cavity tandem brake valve.

[0026] Specifically, the brake valve 6 includes two air inlets and two air outlets, and is integrated with two displacement sensors, which can output the same voltage signal according to the pedal stroke. When a driver steps on the brake pedal of the brake valve 6, the brake valve 6 outputs air pressure, and the air pressure sensor one 21 and the air pressure sensor two 22 can identify the brake intention of the driver and the action of stepping on the brake pedal of the brake valve 6. The two air pressure sensors one 21 and the air pressure sensor two 22 can output the same pedal stroke signal according to the pedal stroke of the brake valve 6. At the same time, the automobile electronic control unit 5 outputs two control signals to the proportional relay valve according to the input signal, and controls the on-off of the proportional relay valve.

[0027] The proportional relay valve can realize air control and electric control, including an air inlet, an air outlet, an exhaust port, an air control interface and an electric control interface, wherein the air inlet is connected with the air cylinder through a pipeline, the air outlet is communicated with the brake chamber through a pipeline, the exhaust port is used for exhausting air, the air control interface is communicated with one of the air outlets of the brake valve 6, and the electric control interface is connected with the electric control unit 5 of the automobile.

[0028] The working principle of the embodiment is as follows.

[0029] When the parking brake is released, the driver operates the hand brake valve 7 to make the air inlet and the air outlet of the hand brake valve 7 communicated, and the compressed air in the air cylinder three 27 enters the control port 7 of the differential relay valve 8 through the hand brake valve 7, so that the air inlet and the air outlet of the differential relay valve 8 are communicated, at this time, the compressed air in the air cylinder three 27 enters the spring cavities of the brake chambers two 12, 13 and 14 through the differential relay valve 8, and the parking brake is released.

[0030] When the driver steps on the brake pedal of the brake valve 6, the air inlet and the air outlet of the brake valve 6 are communicated, and the compressed air in the air cylinder one 25 and the air cylinder two 26 enters the proportional relay valve through the brake valve 6, in this process, the air pressure sensor one 21 and the air pressure sensor two 22 at the air outlet of the brake valve 6 transmit the air pressure signal to the automobile electric control unit 1, the automobile electric control unit 1 judges that there is a driver through the air pressure signal, at this time, the proportional relay valve receives the air path control signal and responds, at this time, the proportional relay valve is not controlled by the signal generated by the displacement sensor integrated in the brake valve 6, when there is a driver, the brake valve 6 line control loop can be used as the redundancy of the air control loop, when the air control loop of the brake valve 6 cannot establish pressure due to air leakage fault, the air pressure sensor one 21 and the air pressure sensor two 22 on the brake valve 6 have no signal, the automobile electric control unit 1 can receive the displacement sensor signal of the brake valve 6 to control the action of the proportional relay valve 5.

[0031] When the vehicle needs to be parked, the electromagnetic valve 10 receives the signal, and the air inlet and air outlet of the electromagnetic valve 10 are disconnected, and at the same time, the air outlet and the exhaust port of the electromagnetic valve 10 are connected, the compressed air in the differential relay valve 8 control port loop is discharged through the exhaust port of the electromagnetic valve 10, the air inlet and the air outlet of the differential relay valve 8 are disconnected, and the compressed air in the spring cavities of the brake chambers 12, 13 and 14 is discharged through the exhaust port of the differential relay valve 8, and the springs in the brake chambers 12, 13 and 14 push the push rods to perform parking brake.

[0032] When the vehicle needs to be braked, the vehicle controller sends a braking demand to the automobile electronic control unit 5, the automobile electronic control unit 5 outputs a control signal to the electric control interface of the proportional relay valve through the signal to control the air pressure output of the proportional relay valve, and the compressed air in the air cylinders 25 and 26 enters the brake chamber through the proportional relay valve, and the push rod of the chamber acts on the wheel brake to brake. The air pressure output of the proportional relay valve has a certain curve relationship with the braking force of the wheel brake, and during the braking process, the air pressure sensors 23 and 24 of the air outlet of the proportional relay valve 16 and the proportional relay valve 3 collect the air pressure signals and feed back to the automobile electronic control unit 5, when the braking force represented by the air pressure signal does not meet the demand issued by the vehicle controller, the automobile electronic control unit 5 adjusts the output air pressure by adjusting the opening degree of the proportional relay valve, forming a control closed loop.

[0033] When the vehicle is in the parking state, the differential relay valve 8 receives the compressed air provided from the air outlet of the proportional relay valve 2 to connect the air inlet and the air outlet of the differential relay valve 8, and the parking brake is released. That is, the parking brake does not work when the service brake is working, and the purpose is to prevent the push rod from being deformed or the brake from being faulty due to the superimposed force of the chamber push rod and the superimposed force of the chamber service cavity and the parking cavity.

[0034] The preferred embodiments of the utility model are only used for limiting the utility model, and the utility model can have various changes and changes for the person skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A brake-by-wire pneumatic braking system for an ultra-heavy special off-road vehicle, characterized in that: The air compressor, condenser, air dryer, four-loop protection valve, automobile electronic control unit, brake valve, air cylinder, brake chamber, hand brake valve, the brake valve is provided with a proportional relay valve on the connecting gas path of the brake chamber, the air inlet of the brake valve and the proportional relay valve is connected with the air cylinder, the air outlet of the brake valve and the proportional relay valve is integrated with a gas pressure sensor, the brake valve, proportional relay valve and gas pressure sensor are electrically connected with the automobile electronic control unit, the hand brake valve is provided with a differential relay valve on the connecting gas path of the brake chamber for parking, the air inlet of the hand brake valve and the differential relay valve is connected with the air cylinder, the air outlet of the differential relay valve is integrated with a low air pressure alarm switch, and the hand brake valve is provided with an electromagnetic valve in parallel.

2. The brake-by-wire system of claim 1, wherein: The brake valve is provided with two gas control loops, the brake chamber and proportional relay valve control correspondingly provided with five groups, the first two groups of brake chambers are used for the front axle of the vehicle, and the corresponding two groups of proportional relay valves are controlled by one gas control loop, and the last two groups of brake chambers are used for the rear axle of the vehicle, and the corresponding three groups of proportional relay valves are controlled by another gas control loop.

3. The brake-by-wire system of claim 1, wherein: The air cylinder is provided with four groups, wherein two groups of air cylinders are connected to the gas control loop of the brake valve and the proportional relay valve of the front and rear axles of the vehicle respectively, and are used for adjusting the air pressure of the brake chamber of the front and rear axles of the vehicle, the third group is used for the parking loop, and the fourth group is used for auxiliary braking.

4. The brake-by-wire system of claim 3, wherein: Each air cylinder is provided with a drain valve.

5. The brake-by-wire system of claim 1, wherein: The brake valve adopts a double-cavity tandem brake valve.

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