Malfunctioning Pneumatic braking system prevented by a kind of vehicleTechnical field
The present invention relates to a kind of motor vehicle braking system, say that relating to a kind of vehicle be arranged on big-and-middle-sized over-the-road transportation vehicle prevents malfunctioning Pneumatic braking system accurately.
Background technology
The safety of running car and the reliability of brake system closely related.And advantages such as Pneumatic braking system is high with its reliability, fast response time, low cost of manufacture, use is pollution-free and being widely used on Medium or severe type goods carrying vehicle and motor omnibus.Existing Pneumatic braking system is mainly provided with two and overlaps independently brake equipment, i.e. holding brake device and service braking device.During service brake, chaufeur controls two-chamber main brake valve by stretcher, high pressure gas in gascollecting cap cylinder are sent in each brake cylinder of the forward and backward bridge of vehicle through two-chamber main brake valve respectively, high pressure gas promote brake cylinder work, and the push rod of each brake cylinder stretches out and drives brake wheel to realize service brake.During parking, close park brake switch, the gas circuit between cut off high storage tank and back axle brake cylinder, meanwhile, the high pressure gas in back axle brake cylinder enter air, and energy stroage spring is released through push rod and drives brake wheel to realize braking during standstill.When removing parking, open park brake switch, the high pressure gas of gascollecting cap cylinder are entered in back axle brake cylinder by park brake switch, the pressure compressed energy-storage spring utilizing high pressure gas to produce, drive in pusher retracted brake cylinder, the braking effect of back axle brake cylinder is removed.In a particular application, for preventing because of the excessive damage drg of braking force and linkage part in vehicle travel process, the spring energy-storage braking in holding brake device and the main compression air brake in service braking device are forbidden overlapping and are used.The Medium or severe type goods carrying vehicle of Pneumatic braking system and motor omnibus are installed in the process of moving because of the wearing and tearing of brake component and the impact of ambient environment, there will be freeze blocking, system element ponding of cryogenic system pipeline ponding unavoidably to freeze the fault such as hair fastener, the gas leakage of high/low temperature system failure, car brakeing air pressure is easily caused to reduce, when braking pressure is lower than 0.55Mpa, car brakeing can be caused malfunctioning, thus cause major motor vehicle safety misadventure, therefore there is larger potential safety hazard in existing Pneumatic braking system.
Summary of the invention
The object of the invention is: providing a kind of can reduce and the vehicle that compensates indicating brake action rapidly under leakage situation timely and effectively prevents malfunctioning Pneumatic braking system, to improve Pneumatic braking system at infrabar or without the deceleration and stopping performance under atmospheric pressure state at air pressure.
Technical scheme of the present invention is: malfunctioning Pneumatic braking system prevented by a kind of vehicle, comprise the air compressor connected successively by gas path pipe, air filter, four-loop protection valve and high-pressure gas cylinder and be divided into propons brake cylinder and the back axle brake cylinder of propons and back axle, inflation compressed air brake cylinder and bleeder brake air chamber is equipped with in described propons brake cylinder and back axle brake cylinder, at described high-pressure gas cylinder and front, control for brake valve module is also connected with between back axle brake cylinder, it is characterized in that, described control for brake valve module comprises anti-failure brake master valve, anti-malfunctioning three control relay valves, intelligence Air Cut Valve, manual parking valve and front, back axle single control relay valve,
Described anti-failure brake master valve is side-by-side configuration, it comprises valve body, valve body is respectively equipped with the propons admission port for controlling propons service brake, propons air extractor duct, propons controls admission port and propons controls air extractor duct and back axle admission port, back axle air extractor duct, back axle control admission port and back axle for controlling back axle service brake control air extractor duct;
Described anti-malfunctioning three control relay valves comprise relay valve body, be slidably mounted on valve body by sealing respectively in relay valve body, the upper relay piston of below and lower relay piston are every being provided with upper chamber, valve pocket and lower chamber, offer at the top of relay valve body be communicated with upper chamber first control admission port, double-way check valve is provided with in the bottom of relay valve body, two imports of this double-way check valve are respectively the second control admission port and the 3rd be arranged on relative body wall and control admission port, the outlet of this double-way check valve is communicated with lower chamber, be slidably fitted with in double-way check valve and control admission port or the 3rd and control for controlling described outlet and described second sliding valve core that admission port is communicated with, vertically on the middle part sidewall of relay valve body be interval with air extractor duct with lower admission port and be provided with the exhausr port being connected air, on in valve pocket, lower interval be provided with servo valve seat and lower servo valve seat, upper servo valve seat is connected with upper air extractor duct, lower servo valve seat is connected with lower admission port, on chamber wall in the middle part of valve pocket, sealing is fixed with valve sleeve, upper at valve sleeve, lower two ends seal respectively and are slidably fitted with servo spool and lower servo spool, valve sleeve with on, spring is top-loaded with respectively between lower servo spool, described servo upper valve core, lower servo spool coordinates upper with described valve sleeve, cavity between lower servo valve seat is divided into air chamber of giving vent to anger successively, exhaust air chamber and air inlet air chamber, described air chamber of giving vent to anger is connected by the air flue be located in relay valve body with air inlet air chamber, on described servo spool with vertically offer the exhaust hole being communicated with exhaust air chamber in lower servo spool respectively, the exhaust passage being communicated with exhaust air chamber and exhausr port is also provided with in valve sleeve with relay valve body, relay piston bottom surface is convexly equipped with the convex platform be sealed and matched with upper servo spool end face through servo valve seat on described down on described, the external diameter of this convex platform is less than servo valve seat bore and is greater than the internal diameter of exhaust hole in servo spool, the lower bulge coordinated with lower servo spool sealing bottom surface through described lower servo valve seat is convexly equipped with at the end face of lower relay piston, the external diameter of this lower bulge is less than lower servo valve seat bore and is greater than the internal diameter of lower relay valve in-core exhaust hole,
Described intelligent Air Cut Valve comprises valve body of dying, be arranged with priority valve and main valve dying in valve body, be in transmission connection by lever transmission mechanism between this priority valve and main valve, described priority valve comprises the guide's valve pocket be located in valve body, the arrival end of this guide's valve pocket communicates with the admission port that valve body is arranged, the exit end of this guide's valve pocket is communicated with the arrival end of main valve by the free air diffuser in valve body, vertically seal slidable fit on the top of this guide's valve pocket and have guide piston, the bottom surface of this guide piston is the load bearing face connecting admission port and free air diffuser, push rod is fixed with in the upper end of this guide piston, the input end of upper surface and described lever transmission mechanism that the end of push rod passes valve body of dying is in transmission connection, main valve comprises the main valve chamber be located in valve body, be located at the main valve seat between main valve chamber and free air diffuser and be located at the main valve plug be sealed and matched by top pressure spring and described main valve seat in main valve chamber, the arrival end of this main valve chamber is communicated with described free air diffuser by main valve seat, the exit end of this main valve chamber is communicated with the air extractor duct that valve body is arranged by outlet passageway, the push rod upwards extended is fixed with on the top of described main valve plug, the slide mouth of the upper surface and described lever transmission mechanism that pass valve body of dying of this push rod seal is in transmission connection, also exhausr port is provided with in the bottom of described main valve chamber, to be connected with when opening or close main valve close synchronously in the bottom of described main valve plug with one heart by adapter sleeve or to open the exhaust plug of this exhausr port, pressure sensor is connected with in the side of main valve chamber, this pressure sensor is connected with low-pressure alarming device,
Described anti-malfunctioning three control relay valves are provided with propons and prevent that malfunctioning three control relay valves prevented by malfunctioning three control relay valves and back axle, described intelligent Air Cut Valve is provided with propons Air Cut Valve and back axle Air Cut Valve, at described manual parking valve and front, back axle single control relay valve is respectively arranged with admission port, air extractor duct and exhausr port, front, back axle single control relay valve is also respectively equipped with control gas port, the admission port of described manual parking valve, propons admission port in anti-failure brake master valve and back axle admission port, admission port in propons Air Cut Valve and back axle Air Cut Valve, propons prevents that malfunctioning three control relay valves and back axle prevent that malfunctioning three control the lower admission port of relay valve and front, the admission port of back axle single control relay valve is connected with high-pressure gas cylinder respectively by pipeline, the propons air extractor duct of described anti-failure brake master valve is connected respectively by pipeline is corresponding with the control gas port on propons single control relay valve and back axle single control relay valve with back axle air extractor duct, propons single control relay valve is connected with the inflation compressed air brake cylinder in front brake cylinder and rear brake cylinder respectively with the air extractor duct of back axle single control relay valve, simultaneously, respectively by pipeline branch road and propons, the air extractor duct of propons single control relay valve and back axle single control relay valve prevents that malfunctioning three control relay valve, back axle prevents that the 3rd of malfunctioning three control relay valves the controls the connection of admission port correspondence, the propons of described anti-failure brake master valve controls admission port and back axle controls admission port respectively by pipeline and propons Air Cut Valve, the air extractor duct correspondence of back axle Air Cut Valve connects, propons in anti-failure brake master valve controls air extractor duct and respectively by pipeline and propons, back axle control air extractor duct prevents that malfunctioning three control relay valve, back axle prevents that first on malfunctioning three control relay valves control admission port correspondence and connect, by pipeline, the air extractor duct of described manual parking valve prevents with propons that malfunctioning three control relay valve and back axle and prevent that malfunctioning three control second of relay valve and control admission port and be connected respectively, described propons prevents that the upper air extractor duct of malfunctioning three control relay valves is connected with the bleeder brake air chamber of propons brake cylinder by pipeline, described back axle prevents that the malfunctioning three control upper air extractor ducts of relay valve are connected with the bleeder brake air chamber of back axle brake cylinder.
Leverage in described intelligent Air Cut Valve comprises active laver assembly and the passive lever assembly of transmission cooperation, described active laver assembly comprises the lever support be located in push rod end and the active laver being arranged in lever support, described passive lever assembly comprises spring and sticks up seat and be located at spring and stick up passive lever on seat, spacing cooperation is pressed by the top permanent seat top with valve body of dying is arranged in one end of described active laver, the input end top that its other end and described spring stick up seat presses transmission to coordinate, described passive lever is fixedly mounted on spring and sticks up on the mouth of seat, spacing cooperation is pressed by top and described permanent seat top in its one end, its other end and described push rod top are pressed and are in transmission connection.
Described spring sticks up seat primarily of cylindrical spring and the power input spring perch and the Power output spring perch composition that are separately fixed at cylindrical spring two ends, described power input spring perch is connected with active laver, described Power output spring perch rotates and is assemblied on permanent seat, and described passive lever and this spring stick up between seat and be obliquely installed.
Described intelligent Air Cut Valve is also provided with main air pressure adjusting mechanism and assist gas pressure adjusting mechanism, described main air pressure adjusting mechanism comprises the adjusting pole be installed on described permanent seat, the adjustment screw of spinning on adjusting pole and top are contained in the pressure spring between adjustment screw and lever support, described assist gas pressure adjusting mechanism comprises sealing and is slidably mounted on the adjustment piston of dying in valve body, this adjustment piston is positioned at below described guide piston, the upper end of this adjustment piston contacts with the bottom of guide piston and coordinates, valve body of dying below adjustment piston is provided with auxiliary adjusting seat, auxiliary adjusting seat is installed with auxiliary adjustment screw, auxiliary adjustment spring is top-loaded with between auxiliary adjustment screw and adjustment piston.
Exhaust plug sealing described in described intelligent Air Cut Valve is slidably mounted in adapter sleeve, and the bottom of this exhaust plug coordinates with adapter sleeve end opening limit block, in adapter sleeve, be top-loaded with spring bottom main valve plug and between exhaust plug top.
Vehicle of the present invention prevents that malfunctioning Pneumatic braking system is by anti-failure brake master valve, front-rear axle prevents the cooperation of malfunctioning three control relay valves and front-rear axle intelligence Air Cut Valve, can occur that cryogenic system pipeline ponding freezes blocking at vehicle, system element ponding freezes hair fastener, faults such as high/low temperature system failure gas leakage and when causing brake system air pressure lower than 0.55Mpa, energy stroage spring in rapid release brake cylinder, the energy stroage spring of braking during standstill is utilized to carry out effective compensation to the indicating brake action of vehicle, thus the driving safety performance of vehicle can be guaranteed, avoid occurring the major traffic accidents such as personal casualty, anti-malfunctioning Pneumatic braking system of the present invention is simple to operate, easy to use, safe and reliable, solve existing vehicle in infrabar or the problem that there will be braking failure without air pressure, there is good Social benefit and economic benefit, be suitable at various lorry, passenger vehicle is installed and used.
Accompanying drawing explanation
Fig. 1 is the structural representation that malfunctioning Pneumatic braking system prevented by vehicle of the present invention;
Fig. 2 is the structural representation of anti-malfunctioning three control relay valves in Fig. 1;
Fig. 3 is the structural representation of intelligent Air Cut Valve in Fig. 1.
Detailed description of the invention
Vehicle of the present invention prevents the specific embodiment of malfunctioning Pneumatic braking system as shown in Figure 1, its primarily of air compressor 1, air filter 2, four-loop protection valve 3, high-pressure gas cylinder 4, brake pedal 5, anti-failure brake master valve 6, manual parking valve 8, propons single control relay valve 10, propons brake cylinder 11, propons drg 12, back axle single control relay valve 14, back axle brake cylinder 16, rear axle brake vi 17, low pressure alarm 18, air-pressure gauge 19 and anti-malfunctioning three control relay valves and intelligent Air Cut Valve composition.
Wherein, anti-failure brake master valve is side-by-side configuration, it comprises valve body, valve body is respectively equipped with the propons admission port for controlling propons service brake, propons air extractor duct, propons controls admission port and propons controls air extractor duct and back axle admission port, back axle air extractor duct, back axle control admission port and back axle for controlling back axle service brake control air extractor duct.This anti-failure brake master valve is prior art, and have structure referring to Chinese invention patent application file CN102862562A, can repeat no more herein.
In the present invention, anti-malfunctioning three control relay valves are arranged with propons and prevent that malfunctioning three control relay valves 13 and back axle three control relay valve 15, it is identical that this propons prevents that malfunctioning three control relay valves 13 and back axle three control relay valve 15 structure, prevent that malfunctioning three control relay valves 13 describe in detail its structure for propons herein, specifically as shown in Figure 3, it comprises relay valve body 60, the upper relay piston 61 of upper and lower and lower relay piston 65 is slidably mounted on every being provided with upper chamber by sealing respectively in relay valve body 60, valve pocket and lower chamber, offer at the top of relay valve body 60 be communicated with upper chamber first control admission port 63, double-way check valve is provided with in the bottom of relay valve body 60, two imports of this double-way check valve are respectively the second control admission port 68 and the 3rd be arranged on relative body wall and control admission port 69, the outlet of this double-way check valve is communicated with lower chamber, be slidably fitted with in double-way check valve and control admission port 68 or the 3rd and control for controlling its outlet and second sliding valve core 70 that admission port 69 is communicated with.Vertically on the middle part sidewall of relay valve body 60 be interval with air extractor duct 77 and lower admission port 78 and the exhausr port (depending on not going out in figure) being connected air, on in valve pocket, lower interval be provided with servo valve seat 72 and lower servo valve seat 73, upper servo valve seat 72 is connected with upper air extractor duct 77, lower servo valve seat 73 is connected with lower admission port 78, on chamber wall in the middle part of valve pocket, sealing is fixed with valve sleeve 74, upper at valve sleeve 74, lower two ends seal respectively and are slidably fitted with servo spool 75 and lower servo spool 80, spring is top-loaded with respectively at valve sleeve 74 and between upper servo spool 75 and lower servo spool 80.Upper servo spool 75, lower servo spool 80 coordinates the air chamber of the giving vent to anger cavity between upper servo valve seat 72 and lower servo valve seat 73 being divided into successively top with valve sleeve 74, the exhaust air chamber at middle part and the air inlet air chamber of bottom, wherein, air chamber of giving vent to anger is connected by the interface channel 80 be located in relay valve body with air inlet air chamber, simultaneously, the upper exhaust bore 76 of servo valve seat 72 and exhaust air chamber in connection is vertically offered in upper servo spool 75, the lower exhaust hole 81 of servo valve seat 73 and exhaust air chamber under connection is vertically offered in lower servo spool 80, the exhaust passage 79 being communicated with exhaust air chamber and exhausr port is also provided with in valve sleeve 74 with relay valve body 60.The bottom surface of upper relay piston 61 be convexly equipped with down through on servo valve seat 72 convex platform 64 be sealed and matched with upper servo spool 75 end face, the external diameter of this convex platform 64 is less than servo valve seat 72 internal diameter and is greater than the internal diameter of upper exhaust hole 76 in servo spool 75, be convexly equipped with through lower servo valve seat 73 at the end face of lower relay piston 65 and the lower bulge 66 coordinated with lower servo spool 80 sealing bottom surface, the external diameter of this lower bulge 66 is less than the internal diameter of lower servo valve seat 73 and is greater than the internal diameter descending exhaust hole 81 in lower servo spool 80.
In the present invention, intelligent Air Cut Valve is divided into propons Air Cut Valve 9 and back axle Air Cut Valve 7, and this propons Air Cut Valve 9 is identical with back axle Air Cut Valve 7 structure, describes in detail for propons Air Cut Valve 9 to its structure herein.Concrete it comprises valve body 83 of dying as shown in Figure 3, is arranged with priority valve and main valve dying in valve body 83, is provided with the lever transmission mechanism of be in transmission connection priority valve and main valve at the top of valve body 83 of dying.Wherein, priority valve comprises the guide's valve pocket be located at and died in valve body 83, the arrival end of this guide's valve pocket communicates with the admission port 84 that valve body 83 of dying is arranged, the exit end of this guide's valve pocket is communicated with the arrival end of main valve by the free air diffuser 99 in valve body, vertically seal slidable fit on the top of this guide's valve pocket and have guide piston 86, the bottom surface of this guide piston 86 is the load bearing face connecting admission port 84 and free air diffuser 99, push rod 87 is fixed with one heart in the upper end of this guide piston 86, the end of push rod 87 upwards passes the die upper surface of valve body 83 and the input end of lever transmission mechanism and is in transmission connection.Main valve comprises the main valve chamber be located at and died in valve body 83, be located at the main valve seat between main valve chamber with free air diffuser 99 and be located in main valve chamber by the corresponding main valve plug 101 be sealed and matched of top pressure spring and main valve seat, the arrival end of this main valve chamber is communicated with free air diffuser 99 by main valve seat, the exit end of this main valve chamber is communicated with the air extractor duct that valve body is arranged (depending on not going out in figure) by outlet passageway 102, the push rod 100 be fixed with one heart on the top of main valve plug 101, this push rod 100 upwards extends sealing the die upper surface of valve body 83 and the mouth of lever transmission mechanism of the place of wearing that slide and is in transmission connection.The exhausr port 105 connecting air is also provided with in the bottom of main valve chamber, noise elimination sieve 106 is provided with outside exhausr port 105, adapter sleeve 103 is fixed with one heart in the bottom of main valve plug 101, be slidably fitted with in adapter sleeve 103 and the exhaust plug 104 for opening and closing exhausr port 105, this exhaust plug 104 coordinates with limit block bottom adapter sleeve 103, between main valve plug 101 and exhaust plug 104, spring is top-loaded with in adapter sleeve 103, it is when main valve plug 101 is opened or closed main valve, and exhaust plug 104 can close synchronously or unlatching exhausr port 105.Leverage comprises active laver assembly and the passive lever assembly of transmission cooperation, wherein, active laver assembly comprises the lever support 88 be located in push rod 87 end and the active laver 89 be arranged in lever support 88, relatively in lever support 88 be convexly equipped with the fin being clamped in active laver about 89 both sides for a pair, this fin forms the fulcrum of active laver 89.Passive lever assembly comprises spring and sticks up seat and be located at spring and stick up passive lever 96 on seat, spring stick up seat primarily of cylindrical spring 93 and be separately fixed at cylindrical spring 93 two ends power input spring perch 94 and Power output spring perch 95 form, Power output spring perch 95 rotates and is assemblied on permanent seat 90 that relay valve body 83 top sets firmly, what passive lever 96 tilted is fixedly mounted on Power output spring perch 95, one end of active laver 89 by top with permanent seat 90 spacing top force fit, the other end of active laver 89 inputs spring perch 94 by the top power stuck up in seat with spring and pushes up and press transmission to coordinate, spacing cooperation is pressed by top to push up with permanent seat 90 in one end of passive lever, the other end of passive lever 96 and push rod 100 push up pressure and are in transmission connection, permanent seat 90 is positioned at above passive lever 96 and is also fixed with locating dowel pin 97.When guide piston 86 is up by gas pressure, push rod 87 drives active laver 89 upwards to swing by lever support 88, active laver 89 drives power to input spring perch 94 and is upturned, under cylindrical spring 93 acts on, spring sticks up seat and swings, Power output spring perch 95 rotates thus makes passive lever 96 swing by push rod 100 downwards and makes main valve plug 101 descending, opens main valve.Intelligent Air Cut Valve is also provided with main air pressure adjusting mechanism and assist gas pressure adjusting mechanism, wherein, main air pressure adjusting mechanism comprises adjustment screw 91 on adjusting pole of the adjusting pole be installed on permanent seat 90, spinning and top and is contained in pressure spring 92 between adjustment screw 91 and lever support 88.Assist gas pressure adjusting mechanism comprises sealing and is slidably mounted on the adjustment piston 109 of dying in valve body 83, this adjustment piston 109 is positioned at the below of guide piston 86, the upper end of this adjustment piston 109 contacts with the bottom of guide piston 86 and coordinates, valve body 83 of dying below adjustment piston 109 is provided with auxiliary adjusting seat, auxiliary adjusting seat is installed with auxiliary adjustment screw 108, auxiliary adjustment spring 110 is top-loaded with between auxiliary adjustment screw 108 and adjustment piston 109, in addition, valve body 83 is positioned at main air pressure adjusting mechanism and leverage is also covered with seal closure 98 outward dying, the auxiliary adjusting seat of assist gas pressure adjusting mechanism also seals and is fixed on valve body 83 bottom of dying, also be provided with communication seals cover 98 dying in valve body 83, the air pressure balance duct 107 of auxiliary adjusting seat and exhausr port.Be connected with pressure sensor 111 in the side of main valve chamber, this pressure sensor 111 is connected with low pressure alarm 16.
Air compressor 1 in anti-malfunctioning Pneumatic braking system of the present invention, air filter 2, four-loop protection valve 3, high-pressure gas cylinder 4, brake pedal 5, manual parking valve 8, propons single control relay valve 9, propons brake cylinder 10, propons drg 11, back axle single control relay valve 12, back axle brake cylinder 13, rear axle brake vi 14 etc. is prior art, wherein, at manual parking valve 8, propons single control relay valve 10 and back axle single control relay valve 14 are respectively arranged with admission port, air extractor duct and exhausr port, propons single control relay valve 10 and back axle single control relay valve 14 are also respectively equipped with control gas port.The admission port of manual parking valve 8, propons admission port in anti-failure brake master valve 6 and back axle admission port, admission port in propons Air Cut Valve 9 and back axle Air Cut Valve 7, propons prevents with back axle, malfunctioning three control relay valves 13 prevent that the admission port of the malfunctioning three lower admission ports and propons single control relay valve 10 and back axle single control relay valve 14 controlling relay valve 15 is connected with high-pressure gas cylinder 4 respectively by pipeline, the propons air extractor duct of anti-failure brake master valve 6 is connected respectively by pipeline is corresponding with the control gas port on propons single control relay valve 10 and back axle single control relay valve 14 with back axle air extractor duct, propons single control relay valve 10 is connected with the inflation compressed air brake cylinder in front brake cylinder 11 and rear brake cylinder 16 respectively with the air extractor duct of back axle single control relay valve 14, simultaneously, respectively by pipeline branch road and propons, the air extractor duct of propons single control relay valve 10 and back axle single control relay valve 14 prevents that malfunctioning three control relay valve 13, back axle prevents that the 3rd of malfunctioning three control relay valves 15 the controls the connection of admission port correspondence, the propons of anti-failure brake master valve 6 controls admission port and back axle controls admission port respectively by pipeline and propons Air Cut Valve 9, the air extractor duct correspondence of back axle Air Cut Valve 7 connects, propons in anti-failure brake master valve 6 controls air extractor duct and respectively by pipeline and propons, back axle control air extractor duct prevents that malfunctioning three control relay valve 13, back axle prevents that first on malfunctioning three control relay valves 15 control admission port correspondence and connect, by pipeline, the air extractor duct of manual parking valve 8 prevents with propons that malfunctioning three control relay valve 13 and back axle and prevent that malfunctioning three control second of relay valve 15 and control admission port and be connected respectively, propons prevents that the upper air extractor duct of malfunctioning three control relay valves 13 is connected with the bleeder brake air chamber of propons brake cylinder 11 by pipeline, back axle prevents that the malfunctioning three control upper air extractor ducts of relay valve 15 are connected with the bleeder brake air chamber of back axle brake cylinder 16.
When the system pressure in vehicle air brake system is normal, one road air pressure enters in propons Air Cut Valve 9 and back axle Air Cut Valve 7 respectively, the effect of being stressed of guide piston 86 in propons Air Cut Valve 9 and back axle Air Cut Valve 7 is up, promoted by leverage that main valve plug 101 is descending opens air extractor duct and close exhausr port 105, make this propons Air Cut Valve 9 and back axle Air Cut Valve 7 all be in normally open, the forward and backward bridge that high pressure gas send into anti-failure brake master valve 6 through propons Air Cut Valve 9 and back axle Air Cut Valve 7 respectively controls in admission port 52; Another road air pressure enters anti-failure brake master valve 6 and by forward and backward bridge control air extractor duct, high pressure gas sent into propons respectively prevents that malfunctioning three control relay valves 13 and back axle prevent that first of malfunctioning single control relay valve 15 controls in admission port 63, in promotion, relay piston 61 is descending, it is descending that upper relay piston 61 promotes upper servo spool 75 by convex platform 64, opens the passage of servo valve seat 72.When removing parking, manual parking valve 8 is pulled to traveling position, high pressure gas enter propons respectively through manual parking valve 8 and prevent that malfunctioning three control relay valves 13 and back axle prevent that second of malfunctioning three control relay valves 15 controls in admission port 68, under high pressure gas promote in lower chamber, relay piston 65 is up, promote sliding valve core 70 to move to right, closedown the 3rd control admission port 69 is communicated with lower chamber simultaneously.It is up that lower relay piston 65 promotes lower servo spool 80 by lower bulge 66, open the passage of lower servo valve seat 73, make high pressure gas from lower admission port 78 and through lower servo valve seat 73, interface channel 82, upper servo valve seat 72 exports from upper air extractor duct 77, propons prevents that malfunctioning three control relay valves 13 and back axle prevent that the high pressure gas that the upper air extractor duct of malfunctioning three control relay valves 15 exports enter in the bleeder brake air chamber of propons brake cylinder 11 and back axle brake cylinder 16 respectively, air pressure promotes the energy stroage spring compression in brake cylinder, energy stroage spring unclamps propons drg 12 and rear axle brake vi 17 by pipe link, remove parking.When braking in normal driving process, step on brake pedal 5, brake pedal 5 makes anti-failure brake master valve 6 work by connecting rod, high pressure gas output to propons single control relay valve 10 with the control gas port of back axle single control relay valve 14 by the propons air extractor duct of anti-failure brake master valve 6 and back axle air extractor duct respectively, thus open propons single control relay valve 10 and back axle single control relay valve 14 respectively, high pressure gas enter propons brake cylinder 11 with the inflation compressed air brake cylinder of back axle brake cylinder 16 respectively by the admission port of propons single control relay valve 10 and back axle single control relay valve 14 and air extractor duct, realize forming braking.When service brake occurs that system gas forces down in 0.55Mpa, propons Air Cut Valve 9 and back axle Air Cut Valve 7 are closed simultaneously and are connected low pressure alarm 18 for chaufeur warning respectively by pressure sensor 111, propons Air Cut Valve 9 and back axle Air Cut Valve 7 close make the propons in anti-failure brake master valve 6 control into, air extractor duct and back axle control into, air extractor duct is all without air pressure, propons prevents that malfunctioning three control relay valves 13 and back axle prevent that first in malfunctioning three control relay valves 15 control admission port 63 and lose air pressure, up under the gas pressure of upper relay piston 61 in the bleeder brake air chamber of brake cylinder, simultaneously, upper servo spool 75 under the action of the spring up pass closes relay valve seat 72, via propons, propons brake cylinder 11 and the air pressure in bleeder brake air chamber in back axle brake cylinder 16 prevent that malfunctioning three control relay valve 13 and back axle and prevent the malfunctioning three upper air extractor ducts 77 controlling relay valve 15 respectively by pipeline, upper exhaust hole 76 in upper servo spool 75 enters air through exhaust passage 79 from exhausr port, energy stroage spring in propons brake cylinder 11 and back axle brake cylinder 16 is released, simultaneously to front, the indicating brake action of back axle compensates, improve vehicle braking performances.