CN107985284B - Off-highway wide vehicle pneumatic brake system and off-highway wide vehicle - Google Patents

Abstract

The invention provides an off-highway wide-body vehicle pneumatic braking system and an off-highway wide-body vehicle, and relates to the field of off-highway wide-body vehicles. The pneumatic braking system of off-highway wide-body vehicles includes a parking brake system; the parking brake system includes an air source, a four-circuit protection valve, a front air reservoir, a rear air reservoir, a hand brake valve, a front synchronization valve, and a rear synchronization valve. valve, front relay valve, rear relay valve, rear right brake air chamber, rear left brake air chamber, front left brake air chamber and front right brake air chamber; the air source is connected to the four-circuit protection valve, and the four-circuit One of the output ports of the protection valve is connected to the front air reservoir, the other output port of the four-circuit protection valve is connected to the rear air reservoir, the front air reservoir is connected to the hand brake valve, and one of the air outlets of the hand brake valve is synchronized with the front The valve is connected, its other air outlet is connected to the rear synchronization valve, and the front air reservoir is also connected to the air inlet of the front synchronization valve. The pneumatic braking system of off-highway wide-body vehicles has high safety performance and can ensure that the front and rear wheels are locked simultaneously during parking braking.

Description

Off-highway wide-body vehicle pneumatic braking system and off-highway wide-body vehicle

Technical field

The present invention relates to the field of off-highway wide-body vehicles, and specifically to an off-highway wide-body vehicle pneumatic braking system and off-highway wide-body vehicles.

Background technique

At present, in vehicles with pneumatic braking systems for off-highway wide-body vehicles, the braking form generally used for driving brakes is that one set of brake pipes is used for the front wheels and another set of pipes is used for the rear wheels. When the vehicle has one pipe Failure will result in vehicle driving risks. In addition, generally only the rear axle parking brake function is used. The safety factor after the single rear axle parking brake is applied is low. Generally, the brake air chamber of a car is a spring air chamber and the braking force cannot be satisfied. , especially when parking on a slope, because the wide-body vehicle has a larger mass and greater inertia, safety accidents are prone to occur.

Contents of the invention

The object of the present invention is to provide an off-highway wide-body vehicle pneumatic braking system. The off-highway wide-body vehicle pneumatic braking system uses a hand brake valve to act on the front synchronization valve and the rear synchronization valve, so that the front synchronization valve and the rear synchronization valve The valve controls the locking port of the brake air chamber, thereby achieving simultaneous locking of the front and rear wheels during parking braking, which has high safety performance.

Another object of the present invention is to provide an off-highway wide-body vehicle that has all the functions of the above-mentioned off-highway wide-body vehicle pneumatic braking system.

The embodiment of the present invention is implemented as follows:

An air pressure braking system for off-highway wide-body vehicles, including a parking brake system;

The parking brake system includes an air source, a four-circuit protection valve, a front air reservoir, a rear air reservoir, a hand brake valve, a front synchronization valve, a rear synchronization valve, a front relay valve, a rear relay valve, and a rear right brake. air chamber, rear left brake air chamber, front left brake air chamber and front right brake air chamber;

The gas source is connected to the four-circuit protection valve, one of the output ports of the four-circuit protection valve is connected to the front air reservoir, and the other output port of the four-circuit protection valve is connected to the rear air reservoir. , the front air reservoir is connected to the hand brake valve, one of the air outlets of the hand brake valve is connected to the front synchronization valve, the other air outlet is connected to the rear synchronization valve, the front The air reservoir is also connected to the air inlet of the front synchronization valve and the front relay valve. The front synchronization valve is connected to the front relay valve. The front relay valve and the front synchronization valve are also connected respectively. It is connected to the front right brake air chamber and the rear right brake air chamber. The rear air reservoir is also connected to the air inlet of the rear synchronization valve and the rear relay valve. The rear synchronization valve is connected to The rear relay valve is connected, and the rear relay valve and the rear synchronization valve are also connected to the front left brake air chamber and the rear left brake air chamber respectively.

In addition, the pneumatic braking system for off-highway wide-body vehicles provided according to embodiments of the present invention may also have the following additional technical features:

In an optional embodiment of the present invention, the pneumatic braking system for off-highway wide-body vehicles also includes a service braking system;

The service brake system includes an air source, a four-circuit protection valve, a front air reservoir, a rear air reservoir, a foot brake valve, a front relay valve, a rear relay valve, a rear right brake air chamber, and a rear left brake air chamber. , front left brake air chamber and front right brake air chamber;

The gas source is connected to the four-circuit protection valve, one of the output ports of the four-circuit protection valve is connected to the front air reservoir, and the other output port of the four-circuit protection valve is connected to the rear air reservoir. , one of the air inlets of the foot brake valve is connected to the front air reservoir, the other air inlet of the foot brake valve is connected to the rear air reservoir, and one of the foot brake valves The air outlet is connected to the front relay valve, the other air outlet of the foot brake valve is connected to the rear relay valve, and an air inlet of the front relay valve is connected to the front air reservoir, so The front relay valve is also connected to the front right brake air chamber and the rear right brake air chamber respectively. An air inlet of the rear relay valve is connected to the rear air reservoir. The rear relay valve It is also connected to the front left brake air chamber and the rear left brake air chamber respectively.

In an optional embodiment of the present invention, the pneumatic braking system for off-highway wide-body vehicles also includes a combined dryer;

The combined dryer is connected between the air source and the four-circuit protection valve.

In an optional embodiment of the present invention, the off-highway wide-body vehicle pneumatic braking system further includes a regenerative air reservoir;

The regeneration gas storage cylinder is arranged between the combined dryer and the four-circuit protection valve.

In an optional embodiment of the present invention, the gas source is a compressor.

In an optional embodiment of the present invention, the off-highway wide-body vehicle pneumatic braking system further includes a pressure regulating valve;

There are two pressure regulating valves, one of which is disposed between an output port of the four-circuit protection valve and the front air reservoir, and the other one of which is disposed between the Between the other output port of the four-circuit protection valve and the rear air reservoir.

In an optional embodiment of the present invention, the off-highway wide-body vehicle pneumatic braking system further includes a water drain valve;

There are two water discharge valves, one of which is provided at the bottom of the front air reservoir, and the other water discharge valve is provided at the bottom of the rear air reservoir.

In an optional embodiment of the present invention, the off-highway wide-body vehicle air pressure braking system also includes a solenoid valve and an air horn;

The solenoid valve is connected to the front air reservoir, and the air horn is connected to the solenoid valve.

In an optional embodiment of the present invention, the compressor is powered by an engine.

An embodiment of the present invention also provides an off-highway wide-body vehicle, including the above-mentioned pneumatic braking system for the off-highway wide-body vehicle.

The beneficial effects of the embodiments of the present invention are: the pneumatic braking system of the off-highway wide-body vehicle has a reasonable structure and strong practicability, and it can ensure that the front and rear wheels are locked simultaneously during parking braking, so it has high safety performance.

Description of the drawings

In order to explain the technical solutions of the embodiments of the present invention more clearly, the drawings required to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and therefore do not It should be regarded as a limitation of the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic connection diagram of an off-highway wide-body vehicle pneumatic braking system provided in Embodiment 1 of the present invention.

Icon: 1-Compressor; 2-Combined dryer; 3-Regenerative air reservoir; 4-Four-circuit protection valve; 5-Front air reservoir; 6-Rear air reservoir; 7-Rear synchronization valve; 8-Rear right brake Dynamic air chamber; 9-rear relay valve; 10-rear left brake air chamber; 11-hand brake valve; 12-foot brake valve; 13-front relay valve; 14-front left brake air chamber; 15 -Front right brake air chamber; 16-front synchronization valve; 17-air horn; 18-solenoid valve.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, rather than all embodiments. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Therefore, the following detailed description of the embodiments of the invention provided in the appended drawings is not intended to limit the scope of the claimed invention, but rather to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

It should be noted that similar reference numerals and letters represent similar items in the following figures, therefore, once an item is defined in one figure, it does not need further definition and explanation in subsequent figures.

In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "left", "right", "inner", etc. is based on the orientation or positional relationship shown in the drawings, or when the product of the invention is used. The conventionally placed orientations or positional relationships are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply 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. Limitations of Invention.

In the description of the present invention, it should also be noted that, unless otherwise clearly stated and limited, the terms "set" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection, or Integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

Example 1

Referring to Figure 1, an embodiment of the present invention provides an off-highway wide-body vehicle pneumatic braking system. The off-highway wide-body vehicle pneumatic braking system includes an air source, a combined dryer 2, a regeneration air tank 3, and a four-circuit protection valve. 4. Front air reservoir 5, rear air reservoir 6, hand brake valve 11, foot brake valve 12, front synchronization valve 16, rear synchronization valve 7, front relay valve 13, rear relay valve 9, rear right brake air Chamber 8, rear left brake air chamber 10, front left brake air chamber 14 and front right brake air chamber 15.

In this embodiment, the air source is the compressor 1, which is used to generate compressed air. At the same time, the power of the compressor 1 is provided by the engine.

Among them, the pneumatic braking system of off-highway wide-body vehicles includes service braking system and parking braking system.

Referring to Figure 1, the parking brake system mainly uses the following components: air source, four-circuit protection valve 4, front air reservoir 5, rear air reservoir 6, hand brake valve 11, front synchronization valve 16, rear synchronization valve 7. Front relay valve 13, rear relay valve 9, rear right brake air chamber 8, rear left brake air chamber 10, front left brake air chamber 14 and front right brake air chamber 15.

Specifically, the air source is connected to the four-circuit protection valve 4 , one of the output ports of the four-circuit protection valve 4 is connected to the front air reservoir 5 , and the other output port of the four-circuit protection valve 4 is connected to the rear air reservoir 6 .

The front air reservoir 5 is connected to the hand brake valve 11. One of the air outlets of the hand brake valve 11 is connected to the front synchronization valve 16, and the other air outlet of the hand brake valve 11 is connected to the rear synchronization valve 7. The front air reservoir 5 is also connected to the front synchronization valve. The air inlet of 16 is connected to the front relay valve 13. The front synchronization valve 16 is connected to the front relay valve 13. The front relay valve 13 and the front synchronization valve 16 are also respectively connected to the front right brake chamber 15 and the rear right brake chamber. The air chamber 8 is connected, and the rear air reservoir 6 is also connected to the air inlet of the rear synchronization valve 7 and the rear relay valve 9. The rear synchronization valve 7 is connected to the rear relay valve 9. The rear relay valve 9 and the rear synchronization valve 7 are also respectively connected to the front The left brake air chamber 14 and the rear left brake air chamber 10 are connected.

It should be noted that in the parking brake system, the combined dryer 2 is provided in the pipeline between the air source and the four-circuit protection valve 4, and the regeneration air storage tank 3 is provided between the combined dryer 2 and the four-circuit protection valve 4. in the pipeline between valve 4. The combined dryer 2 packs the gas entering the inside of the valve body into dry gas without moisture, thereby extending the service life of the gas valve.

The above-mentioned four-circuit protection valve 4 is provided with gas by the regeneration gas tank 3 .

Referring to Figure 1, in the service brake system, the following components are mainly used: air source, four-circuit protection valve 4, front air reservoir 5, rear air reservoir 6, foot brake valve 12, front relay valve 13, rear relay valve 9. Rear right brake air chamber 8, rear left brake air chamber 10, front left brake air chamber 14 and front right brake air chamber 15.

Specifically, the air source is connected to the four-circuit protection valve 4, one of the output ports of the four-circuit protection valve 4 is connected to the front air reservoir 5, the other output port of the four-circuit protection valve 4 is connected to the rear air reservoir 6, and the foot brake One of the air inlets of the valve 12 is connected to the front air reservoir 5, the other air inlet of the foot brake valve 12 is connected to the rear air reservoir 6, and one of the air outlets of the foot brake valve 12 is connected to the front relay valve 13. , another air outlet of the foot brake valve 12 is connected to the rear relay valve 9, an air inlet of the front relay valve 13 is connected to the front air reservoir 5, and the front relay valve 13 is also connected to the front right brake air chamber 15 , the rear right brake air chamber 8 is connected, an air inlet of the rear relay valve 9 is connected to the rear air reservoir 6, and the rear relay valve 9 is also connected to the front left brake air chamber 14 and the rear left brake air chamber 10 respectively.

It should be noted that in the service brake system, the combined dryer 2 and the regeneration air tank 3 also produce the same functions as in the parking brake system.

It can be seen from the above that during service braking, the air from the air source passes through the combined dryer 2. The moisture in the air is absorbed by the combined dryer 2. After the gas is processed, it flows to the front through the four-circuit protection valve 4. The air reservoir 5 and the rear air reservoir 6, among which the four-circuit protection valve 4 ensures the independence of the air paths of the front air reservoir 5 and the rear air reservoir 6. When one of the pipelines has air leakage or other conditions, the other pipeline Still working fine.

Referring to Figure 1, when the vehicle is in a driving state, when the pedal of the foot brake valve 12 is depressed, the air inlet and outlet of the foot brake valve 12 are connected with the air flow, and the front relay valve 13 and the rear relay valve are immediately opened. The control port of 9 allows the control ports of the front relay valve 13 and the rear relay valve 9 to ventilate. The air outlet of the front relay valve 13 controls the front right brake air chamber 15 and the rear right brake air chamber 8. The rear relay valve 9 The air outlet controls the front left brake air chamber 14 and the rear left brake air chamber 10. At this time, the hand brake valve 11 is in a closed state, and its air port is connected with the air flow of the air outlet. The air outlet of the hand brake valve 11 The air flows to the control port of the front synchronization valve 16 and the control port of the rear synchronization valve 7. At this time, the air inlet and air outlet of the front synchronization valve 16 are connected, and the air inlet and outlet of the rear synchronization valve 7 are connected. The locking ports of the front left brake air chamber 14 and the front right brake air chamber 15 are long vents. The piston rods of the front left brake air chamber 14 and the front right brake air chamber 15 do not have mechanical locking and can extend forward. out to implement service braking.

After the foot brake valve 12 pedal is released, the air inlet and air outlet of the foot brake valve 12 are disconnected, there is no air flow in the control ports of the front relay valve 13 and the rear relay valve 9, and there is no air flow in the air outlet. At this time, the hand The brake valve 11 is in a closed state, the air inlet and air outlet of the hand brake valve 11 are connected, and the air flow from the air outlet of the hand brake valve 11 flows to the control ports of the forward synchronization valve 16 and the rear synchronization valve 7. At this time , the air inlet and outlet of the front synchronization valve 16 and the rear synchronization valve 7 are connected with the air flow, the front right brake air chamber 15, the rear right brake air chamber 8, the front left brake air chamber 14 and the rear left brake air chamber The locking port of the chamber 10 is a long vent. The piston rods of the front right brake air chamber 15, the rear right brake air chamber 8, the front left brake air chamber 14 and the rear left brake air chamber 10 do not have mechanical locking. Retract backward and the service brake is released.

Referring to Figure 1, when the vehicle is in a parking state, the handle of the hand brake valve 11 is pulled up, and the air inlet and outlet of the hand brake valve 11 are disconnected. At this time, the control of the front synchronization valve 16 and the rear synchronization valve 7 The air inlet and outlet of the front synchronization valve 16 and the rear synchronization valve 7 are disconnected, and there is no air flow in the locking port of the front right brake air chamber 15 and the front left brake air chamber 14. At this time, the brake air chamber is Mechanical locking, the foot brake valve 12 is in a released state, the air inlet and outlet of the foot brake valve 12 are disconnected, there is no air flow at the control ports of the front relay valve 13 and the rear relay valve 9, the front relay valve 13 and the rear relay valve 9 There is no air flow in the comparison port of the dynamic valve 9. At this time, the air inlet and air outlet of the front relay valve 13 are connected, the air inlet and the air outlet of the rear relay valve 9 are connected, and the front right brake air chamber 15 and the front left brake air chamber 15 are connected. There is air flow in the brake port of the brake air chamber 14, so that the piston rods of the front right brake air chamber 15, the rear right brake air chamber 8, the front left brake air chamber 14 and the rear left brake air chamber 10 move forward. At the same time, its locking port is mechanically locked to realize parking brake.

After the handle of the hand brake valve 11 is released, the air inlet and outlet of the hand brake valve 11 are connected with air flow, so that there is no air flow in the control ports of the front synchronization valve 16 and the rear synchronization valve 7, and the air inlet of the front synchronization valve 16 It is connected with the air flow of the air outlet, and the air inlet of the rear synchronization valve 7 is connected with the air flow of the air outlet. At this time, the front right brake air chamber 15, the rear right brake air chamber 8, the front left brake air chamber 14 and the rear left There is air flow at the locking port of the brake chamber 10, the foot brake valve 12 is in a released state, the air inlet and air outlet of the foot brake valve 12 are disconnected, and there is no air flow at the control ports of the front relay valve 13 and the rear relay valve 9. , there is air flow at the comparison port of the front relay valve 13 and the rear relay valve 9. At this time, the air inlet and air outlet of the front relay valve 13 are disconnected, and the air inlet and air outlet of the rear relay valve 9 are disconnected. There is no air flow in the brake ports of the right brake air chamber 15, the rear right brake air chamber 8, the front left brake air chamber 14 and the rear left brake air chamber 10, so the parking brake is released.

In this embodiment, the off-highway wide-body vehicle pneumatic braking system also has two pressure regulating valves (not shown in the figure), one of which is disposed between an output port of the four-circuit protection valve 4 and the front air reservoir. 5, another pressure regulating valve is installed between the other output port of the four-circuit protection valve 4 and the rear air reservoir 6. The function of the pressure regulating valve is that it can control the air outlet pressure of the four-circuit protection valve 4. This regulator The pressure valve is suitable for both parking brake systems and service brake systems.

In addition, the pneumatic braking system of the off-highway wide-body vehicle also has two drain valves (not shown in the figure), which are suitable for both the parking brake system and the service brake system.

One of the drain valves is set at the bottom of the front air reservoir 5, and the other drain valve is set at the bottom of the rear air reservoir 6. The function of the drain valve is to regularly drain the front air reservoir 5 and the rear air reservoir when performing maintenance on the entire vehicle. The air reservoir 6 releases water.

In this embodiment, the air pressure braking system of the off-highway wide-body vehicle also includes a solenoid valve 18 and an air horn 17 .

Among them, the solenoid valve 18 is connected to the front air reservoir 5 , and the air horn 17 is connected to the solenoid valve 18 .

In summary, the pneumatic braking system of the off-highway wide-body vehicle has a reasonable structure and strong practicability. It realizes a dual circuit of driving braking and at the same time ensures that the front and rear wheels can be locked at the same time during parking braking, which has a high safety performance.

Example 2

An embodiment of the present invention also provides an off-highway wide-body vehicle, which includes the above-mentioned pneumatic braking system for the off-highway wide-body vehicle.

The off-highway wide-body vehicle has the advantages of the above-mentioned off-highway wide-body vehicle pneumatic braking system.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims (9)

1. An off-highway wide body vehicle pneumatic brake system is characterized by comprising a parking brake system and a service brake system;

the parking brake system comprises an air source, a four-loop protection valve, a front air storage cylinder, a rear air storage cylinder, a hand brake valve, a front synchronous valve, a rear synchronous valve, a front relay valve, a rear right brake air chamber, a rear left brake air chamber, a front left brake air chamber and a front right brake air chamber;

the service brake system comprises the air source, the four-loop protection valve, the front air reservoir, the rear air reservoir, a foot brake valve, the front relay valve, the rear right brake air chamber, the rear left brake air chamber, the front left brake air chamber and the front right brake air chamber;

the air source is connected with the four-loop protection valve, one output port of the four-loop protection valve is connected with the front air storage cylinder, the other output port of the four-loop protection valve is connected with the rear air storage cylinder, the front relay valve is respectively connected with the front right brake air chamber and the rear right brake air chamber, and the rear relay valve is respectively connected with the front left brake air chamber and the rear left brake air chamber;

in the parking braking system, the front air reservoir is connected with the hand braking valve, one air outlet of the hand braking valve is connected with the front synchronous valve, the other air outlet of the hand braking valve is connected with the rear synchronous valve, the front air reservoir is also connected with an air inlet of the front synchronous valve and the front relay valve, the front synchronous valve is also connected with the front relay valve, the front synchronous valve is also respectively connected with the front right braking air chamber and the rear right braking air chamber, the rear air reservoir is also connected with an air inlet of the rear synchronous valve and the rear relay valve, the rear synchronous valve is also connected with the front left braking air chamber and the rear left braking air chamber respectively;

in the service brake system, one air inlet of the foot brake valve is connected with the front air reservoir, the other air inlet of the foot brake valve is connected with the rear air reservoir, one air outlet of the foot brake valve is connected with the front relay valve, the other air outlet of the foot brake valve is connected with the rear relay valve, one air inlet of the front relay valve is connected with the front air reservoir, and one air inlet of the rear relay valve is connected with the rear air reservoir;

when the service braking is realized, a pedal of the foot brake valve is stepped on, so that an air inlet of the foot brake valve is communicated with an air flow of an air outlet, a control port of the front relay valve and the control port of the rear relay valve are opened, so that the air inlets of the front relay valve and the control port of the rear relay valve are ventilated, an air outlet of the front relay valve controls the front right brake air chamber and the rear right brake air chamber, an air outlet of the rear relay valve controls the front left brake air chamber and the rear left brake air chamber, the hand brake valve is in a release state, an air inlet of the hand brake valve is communicated with the air flow of the air outlet of the hand brake valve flows to the control port of the front synchronous valve and the control port of the rear synchronous valve, an air inlet of the front synchronous valve is communicated with the air flow of the air outlet, a locking port of the front left brake air chamber and the front right brake air chamber is a long air vent, and piston rods of the front left brake air chamber and the front right brake air chamber do not produce mechanical locking, and the service braking can be forwards extended;

when the service braking is released, the pedal of the foot brake valve is released, so that the air inlet and the air outlet of the foot brake valve are disconnected, the control ports of the front relay valve and the rear relay valve are free from air flow, the air outlet is free from air flow, the hand brake valve is in a release state, the locking ports of the front right brake air chamber, the rear right brake air chamber, the front left brake air chamber and the rear left brake air chamber are long air ports, and the piston rods of the front right brake air chamber, the rear right brake air chamber, the front left brake air chamber and the rear left brake air chamber are not mechanically locked and can retract backwards to release the service braking;

when parking braking is achieved, a handle of the hand brake valve is pulled up, so that an air inlet and an air outlet of the hand brake valve are disconnected, control ports of the front synchronous valve and the rear synchronous valve are disconnected, air inlets and the air outlets of the front right brake chamber and the front left brake chamber are not connected, the front right brake chamber, the rear right brake chamber, the front left brake chamber and the rear left brake chamber are mechanically locked, the foot brake valve is in a release state, the air inlets and the air outlets of the foot brake valve are disconnected, control ports of the front relay valve and the rear relay valve are not connected, at the moment, the air inlets and the air outlets of the front relay valve are connected, the air inlets of the front right brake chamber, the rear right brake chamber, the front left brake chamber and the rear left brake chamber are connected, the front left brake chamber and the rear brake chamber are connected, and the front left brake chamber is extended, and a parking piston rod is achieved;

when the parking brake is released, the handle of the hand brake valve is released, so that air flows are arranged at locking openings of the front right brake air chamber, the rear right brake air chamber, the front left brake air chamber and the rear left brake air chamber, the foot brake valve is in a release state, at the moment, an air inlet and an air outlet of the front relay valve are disconnected, an air inlet and an air outlet of the rear relay valve are disconnected, and no air flows exist at the locking openings of the front right brake air chamber, the rear right brake air chamber, the front left brake air chamber and the rear left brake air chamber, so that the parking brake is released.

2. The off-road wide body vehicle pneumatic brake system of claim 1, further comprising a combination dryer;

the combined dryer is connected between the air source and the four-loop protection valve.

3. The off-highway wide body vehicle pneumatic brake system of claim 2, further comprising a regenerating air receiver;

the regenerating air receiver is arranged between the combined dryer and the four-loop protection valve.

4. The off-highway wide body vehicle pneumatic brake system of claim 1 or 2, wherein the air source is a compressor.

5. The off-highway wide body vehicle pneumatic brake system of claim 1 or 2, further comprising a pressure regulating valve;

the number of the pressure regulating valves is two, one pressure regulating valve is arranged between one output port of the four-loop protection valve and the front air cylinder, and the other pressure regulating valve is arranged between the other output port of the four-loop protection valve and the rear air cylinder.

6. The off-highway wide body vehicle pneumatic brake system of claim 1 or 2, further comprising a water drain valve;

the number of the water drain valves is two, one water drain valve is arranged at the bottom of the front air storage cylinder, and the other water drain valve is arranged at the bottom of the rear air storage cylinder.

7. The off-highway wide body vehicle pneumatic brake system of claim 1 or 2, further comprising a solenoid valve and an air horn;

the electromagnetic valve is connected with the front air reservoir, and the air horn is connected with the electromagnetic valve.

8. The off-highway wide body vehicle pneumatic brake system according to claim 4, wherein said compressor is powered by an engine.

9. An off-highway wide body vehicle comprising the off-highway wide body vehicle pneumatic brake system of any one of claims 1-8.