SAE J 656-1988 Automotive Brake Definitions and Nomenclature.pdf

1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro

2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.QUESTIONS REGARDING THIS DOCUMENT: (724) 772-8512 FAX: (724) 776-0243TO PLACE A DOCUMENT

3、 ORDER; (724) 776-4970 FAX: (724) 776-0790SAE WEB ADDRESS http:/www.sae.orgCopyright 1988 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001RECOMMENDEDPRACTICESubmitted for recognition as an American National Sta

4、ndardJ656REV.APR88Issued 1952-01Revised 1988-04Superseding J656gAUTOMOTIVE BRAKE DEFINITIONS AND NOMENCLATUREForewordThis Document has also changed to comply with the new SAE Technical Standards Board Format.1. ScopeThis SAE Recommended Practice identifies and defines terms specifically related to b

5、rake systems.2. ReferencesThere are no referenced publications specified herein.3. Definitions3.1 Accumulator A storage container for pressurized fluid.3.2 Air-Assisted Hydraulic Brake SystemA hydraulic type brake system actuated by an air hydraulic powerunit.3.3 Air Brake Low Pressure IndicatorA un

6、it or combination of units which provides a visible and/or audiblesignal whenever the stored air in one of the circuits of an air brake system is below a predetermined value.3.4 Air Brake Low Warning SwitchA device used to complete an electrical circuit to an air brake low pressureindicator.3.5 Air

7、Brake Pressure Protection ValveA unit which prevents the uncontrolled depletion of pressure in onepart of an air brake system when pressure drops below a pre-selected level in another part of the system.3.6 Air Brake ResevoirA storage tank for compressed air.3.7 Air Brake SystemA brake system which

8、utilizes air pressure for operation and control.3.8 Air Brake Trailer Hand Control ValueA hand operated valve for independent graduated control of thetrailer service brake system.3.9 Air Compression GovernorA device which controls the compression of air within a pre-selected range ofpressure.3.10 Ai

9、r Hydraulic Brake Power Assist UnitA unit consisting of air cylinder or chamber, hydraulic cylinder(s)and control valve in which driver effort is combined with force from the cylinder piston or chamber diaphragm todisplace fluid under pressure for actuation of the brake(s).SAE J656 Revised APR88-2-3

10、.11 Air Over Hydraulic Brake SystemSee Air-Assisted Hydraulic Brake System.3.12 Air-Powered Master CylinderA brake master cylinder actuated by an air brake cylinder or chamber.3.13 Air Pressure Reducing ValveA unit which delivers a pre-selected output pressure.3.14 Air-to-Vacuum Conversion Relay Val

11、ve: A unit which converts air signals to related vacuum signals.3.15 Air Vacuum Relay ValveA secondary control unit operated by the control vacuum signal to regulate supplyvacuum to the service brake actuators.3.16 Antiskid Brake SystemA misnomer. See “Wheel Slip Brake Control System.“3.17 Auxiliary

12、 Control ValveA unit which controls pressure in various portions of the brake system.3.18 BrakeAn energy conversion mechanism used to retard, stop, or hold a vehicle.3.19 Brake ActuatorA unit which converts hydraulic pressure, air pressure, vacuum, electrical current or otherforms of energy to a for

13、ce which applies a brake.3.20 Brake AssemblyAn assembly of the non-rotational components of a brake including its mechanism fordevelopment of friction forces.3.21 Brake BoosterA device utilizing a supplementary power source to reduce pedal force in a hydraulic brakesystem.3.22 Brake ChamberA unit wh

14、ich a diaphragm converts pressure to mechanical force for actuation of a brake.3.23 Brake Check Valve - Normally ClosedSee “Check Valve.“3.24 Brake Check Valve - Normally OpenSee “Check Valve.“3.25 Brake CylinderA unit in which a piston converts pressure to mechanical force for actuation of a brake.

15、3.26 Brake DiscThe parallel-faced, circular, rotational member of a brake acted upon by the friction material.3.27 Brake DrumA cylindrical, rotational member of a brake acted upon by the friction material.3.28 Brake Effectiveness BuildupA temporary increase in brake effectiveness during a stop or sn

16、ub.3.29 Brake FluidThe substance, generally in liquid form, used to transmit hydraulic pressure within a brakesystem.3.30 Brake Fluid Level IndicatorA unit in a hydraulic brake system which indicates brake fluid level. See also“Brake System Warning Lamp.“3.31 Brake Fluid Level Warning Switch Assembl

17、yA unit used to actuate a warning device indicating areservoir fluid level lower than a preset value.3.32 Brake HoseA flexible conductor for the transmission of fluid pressure in the brake system.3.33 Brake Hose CouplerA separable mechanical connector for a brake hose between the towing and the towe

18、dvehicle.SAE J656 Revised APR88-3-3.34 Brake Lever or HandleA hand-operated lever or handle which, when actuated, causes the brake(s) to beapplied.3.35 Brake Lining PadA friction material in a plane form. Usual application is on a disc brake shoe.3.36 Brake Lining Wear SensorA unit used to actuate a

19、 warning device indicating a brake lining thickness lessthan a preset value.3.37 Brake PedalA foot-operated lever which, when actuated, causes the brake(s) to be applied.3.38 Brake Power AssistA device installed in a hydraulic brake system that reduces pedal effort.3.39 Brake RetarderAn auxiliary en

20、ergy conversion system used to supplement the service brake system on amoving vehicle.3.40 Brake ShoeThe member which applies the mechanical force of brake application to the brake lining.3.41 Brake Snubbing TimeTime elapsed during a brake snub from the start of brake application to the instantthe l

21、ower speed value is reached.3.42 Brake SnubThe act of retarding a motor vehicle between two positive speed values by the use of a brakesystem.3.43 Brake Stopping DistanceDistance traveled by a motor vehicle from the start of a brake application to thepoint at which the motor vehicle reaches a comple

22、te stop.3.44 Brake Stopping TimeTime elapsed by a motor vehicle from the start of a brake application to the instant themotor vehicle reaches a complete stop.3.45 Brake SystemA combination of one or more brakes and the related means of operation and control.3.46 Brake System Actuation DistanceThe di

23、stance traveled between the start of brake application and theinstant at which a specified brake system pressure is obtained.3.47 Brake System Actuating TimeThe time elapsed between the start of brake application and the instant atwhich a specified brake system pressure is obtained.3.48 Brake System

24、 Warning LampA lamp which is actuated to indicate brake system condition.3.49 Brake Force RatioThe sum of the retarding forces developed by each braked wheel divided by the “astested“ gross weight of the vehicle or combination.3.50 Check ValveA unit which is used to isolate automatically one part of

25、 the brake fluid system from anotherpart.3.50.1 CLOSED TYPEA valve which allows fluid flow in one direction only.3.50.2 OPEN TYPEA valve, normally open to fluid flow in both directions, which closes when fluid flow in onedirection exceeds a predetermined value.3.50.3 RESIDUAL BRAKE PRESSURE TYPEA tw

26、o-function unit in which one function either restricts fluid from thebrake wheel cylinder(s) or retains a pressure in the brake wheel cylinder(s) at the time of brake release, andin which the other function permits fluid compensation for fluid volume changes.SAE J656 Revised APR88-4-3.50.4 TWO-WAY T

27、YPEA unit which permits actuation of a brake system by either of two brake application valves.3.51 Combination Vechicle Brake Connecting Lines (air or vacuum)3.51.1 SUPPLY LINEA flexible conductor terminated by a brake hose coupler, for transmitting supply air or vacuumfrom the towing vehicle to the

28、 towed vehicle.3.51.2 CONTROL LINEA flexible conductor terminated by a brake hose coupler, for transmitting control air orvacuum from the towing vehicle to the towed vehicle.3.52 Differential Pressure Warning Switch AssemblyA unit to actuate a warning device indicating anundesirable pressure differe

29、nce between the separate circuits of a brake system.3.53 Disc BrakeA brake in which the friction forces act upon the faces of a disc(s).3.54 Driver Reaction DistanceThe distance traveled between the point at which the driver perceives a demandfor braking and the start of brake application.3.55 Drive

30、r Reaction TimeThe time elapsed between the instant the driver perceives a demand for braking andthe start of brake application.3.56 Drum BrakeA brake in which the frictional forces act on the cylindrical surface(s) of a brake drum.3.57 Dual Master CylinderA master cylinder for a split brake system

31、having two fluid displacement sections.3.58 Electric Brake3.58.1 ARMATUREThe rotating part of the brake electric actuating mechanism to which the magnet is attracted.3.58.2 CONTROLLERA variable resistance for graduated control of electric brake(s).3.58.3 LOAD COMPENSATING RESISTORA resistor unit in

32、series with an electric brake control which can be preset tolimit current to achieve brake balance.3.58.4 MAGNET The part of the electric actuating mechanism, which when energized, is attracted to the armature,creating a controlled force to apply the brake(s).3.59 Emergency Brake SystemA brake syste

33、m used for stopping a vehicle in the event of a malfunction in themeans of operation and control of the service brake system.3.60 Emergency Valve A unit under the control of the driver which, when actuated, will activate the emergencybrake system.3.61 Equivalent Braking ForceSee “Braking Force Ratio

34、.“3.62 Fade3.62.1 HEAT FADETemporary reduction of brake effectiveness due to a loss of friction between braking surfaces,resulting from heat.3.62.2 WATER FADETemporary reduction of brake effectiveness due to a loss of friction between braking surfaces,resulting from water.SAE J656 Revised APR88-5-3.

35、63 Follow-Up-Type ValveA unit which responds to fluid displacement or mechanical linkage movement, tomodulate pressure in a cylinder or chamber.3.64 Forward ShoeSee “Leading Shoe.“3.65 Foundation Brake AssemblySee “Brake Assembly.“3.66 Glad HandAn air brake hose coupler.3.67 Hold-Off ValveA unit whi

36、ch permits free fluid flow in either direction when the brakes are not applied, butprevents pressure buildup in one part of the brake system until pressure in the other part reaches apredetermined value.3.68 Hydraulic Brake SystemA brake system in which brake operation and control utilizes hydraulic

37、 fluid.3.69 Initial Stopping SpeedSpeed of the motor vehicle at the start of brake application.3.70 Leading ShoeA show in a non-servo brake which pivots around a fulcrum in the direction of normal drumrotation.3.71 Load Proportional Brake ControlA system or device which regulates the input force to

38、the brakes on anaxle in proportion to the load on that axle.3.72 Logic ControllerA part of the wheel slip brake control system which interprets input signals from thesensor(s) and transmits the controlling output signals to the modulator(s).3.73 Manual Hydraulic Brake SystemA hydraulic type brake sy

39、stem which utilizes unassisted driver effort.3.74 Master CylinderThe primary unit for displacing hydraulic fluid under pressure in the brake system.3.75 Metallic Friction MaterialA sintered friction material formulated with metallic or metallic-ceramic materials.3.76 ModulatorThe unit(s) in a wheel

40、slip brake control system which adjust(s) brake actuating force in responseto input signals.3.77 Moisture Ejection ValveA unit which expels fluid contaminants from an air system.3.78 Non-Asbestos Friction MaterialA friction material containing no asbestos.3.79 Non-Servo BrakeA drum brake in which al

41、l brake shoes are independently actuated.3.80 Organic Friction MaterialA friction material, having organic binders, substantially formulated with non-metallic fibers.3.81 Parking Brake Control ValveA valve that controls the parking brake system.3.82 Parking Brake SystemA brake system, intended to ho

42、ld a vehicle stationary, in which one or more brakesmay be held applied without continued application of force to the control.3.83 Parking Brake Warning Switch AssemblyA unit used to actuate a warning device indicating the parkingbrake application mechanism is not in the fully released position.3.84

43、 Proportional Valve (Pressure)A unit in the brake system used to modify the pressure to the brakes on oneor more axles.SAE J656 Revised APR88-6-3.85 Quick Release ValveA control unit which accelerates the release of air pressure from various portions ofbrake systems.3.86 Reactionary Type ValveA unit

44、 which responds to fluid displacement and pressure, or mechanical linkagemovement and force, to modulate pressure in a brake cylinder or chamber.3.87 Relay Emergency ValveA relay valve which also provides for automatic application of the trailer brakes incase of a breakaway or loss of pressure in th

45、e trailer supply (emergency) line.3.88 Relay ValveA control unit used to accelerate the air application and release of air pressure or vacuum in apart of the air system or vacuum brake system.3.89 Reverse ShoeSee “Trailing Shoe.“3.90 Safety ValveA pressure release unit used to protect the air system

46、 against excessive pressure.3.91 Semi-Metallic Friction MaterialA friction material having organic binders formulated with metallic fibersand/or metal powders.3.92 Service Brake SystemThe brake system generally used for retarding or stopping a vehicle.3.93 Service Brake ValveA foot-operated unit whi

47、ch is used for graduated control of all the brakes in the servicebrake system.3.94 Servo BrakeA drum brake in which brake shoes are linked, such that the braking force of one shoe amplifiesthe input of the other shoe(s).3.95 SlackBrake actuator stroke prior to effective application of force.3.96 Sla

48、ck AdjusterAn adjustable member which transmits brake application force and permits compensation forlining wear.3.97 Spitter ValveSee “Moisture Ejection Valve.“3.98 Split Brake SystemA service brake system having two or more separate fluid, electrical, mechanical orother circuits which upon failure

49、in any circuit retains full or partial brake actuating capability.3.99 Spring Type Brake ActuatorA unit which utilizes the stored energy in a spring(s) to actuate the brake(s).3.100 Start of the Brake ApplicationThe instant at which the brake control system is actuated as determinedby initial brake control movement.3.101 Stop Light SwitchA switch which completes the electrical circuit to the stop lamp(s) when the brake(s) is(are) applied.3.102 Straight Air Brake SystemSee “Air Bra