SAEAS1145BV002(飞机刹车温度监控系统).pdf

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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 therefrom,is

2、 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.Copyright 1998 Society of Automotive Engineers,Inc.All rights reserved.Printed in U.S.A.QUESTION

3、S REGARDING THIS DOCUMENT:(724)772-8510FAX:(724)776-0243TO PLACE A DOCUMENT ORDER:(724)776-4970FAX:(724)776-0790SAE WEB ADDRESShttp:/www.sae.org400 Commonwealth Drive,Warrendale,PA 15096-0001AEROSPACE STANDARDSubmitted for recognition as an American National StandardAS1145REV.BIssued1973-04Revised19

4、98-02Superseding AS1145AAircraft Brake Temperature Monitor Systems(BTMS)FOREWORDChanges in this revision are format/editorial only.TABLE OF CONTENTS1.SCOPE.21.1Purpose.22.APPLICABLE DOCUMENTS.23.GENERAL REQUIREMENTS.33.1Function.33.1.1 Design Objectives.33.2Material and Workmanship.53.3Identificatio

5、n.53.4Design and Construction.63.5System Components.63.6Electrical Operation.63.7Sensor.63.8Operating Conditions.64.QUALIFICATION.74.1Sensor.74.2Indicator Unit.94.3Reference Junction or Compensator.105.RELIABILITY.126.MAINTAINABILITY.12SAE AS1145 Revision B-2-1.SCOPE:This specification covers minimu

6、m requirements for brake temperature monitoring equipment whenever used on any type and model of civil aircraft.It shall be the responsibility of the purchaser to determine the compatibility of these requirements with the application aircraft and to specify requirements in excess of these minimums a

7、s necessary.1.1Purpose:To specify minimum requirements for brake temperature monitoring systems for civil aircraft applications.2.APPLICABLE DOCUMENTS:Materials,processes,and standard products shall be selected in accordance with specifications or standards from the sources indicated below in the or

8、der of precedence shown.The issue in effect on date of invitation for bids shall apply.(a)Industry Specifications and Standards as listed in indexes published by recognized industrial associations including but not limited to the following,without order of precedence:(1)Aerospace Material Specificat

9、ions(AMS),Aerospace Standards(AS),Aerospace Recommended Practices(ARP),and Aerospace Information Reports(AIR)published by Society of Automotive Engineers.(2)National Aircraft Standards(NAS)as published by the National Aircraft Standards Committee of the Aerospace Industries Association.(b)Federal sp

10、ecifications and standards as listed in the index of Federal Specifications,Standards,and Handbooks published by the General Service Administration.(c)Military Specifications and Standards as listed in the Department of Defense Index of Specifications and Standards.The following documents are listed

11、 as a minimum and are considered the more important of the reference list given below.The documents that apply shall be of the issue in effect at the time of invitation for bids(including change notices)and shall apply to the extent specified herein.RTCA/DO-160Environmental Conditions and Test Proce

12、dures for Airborne EquipmentMIL-E-5400Electronic Equipment,Airborne,General Specification for.MIL-C-83723Connector Electrical,Circular,Environmental Resisting,Receptacle and Plug,General Specification forMIL-STD-810Environmental Test MethodsMIL-STD-461Electromagnetic Interference Characteristics,Req

13、uirements for EquipmentMIL-STD-130Identification Marking of U.S.Military PropertyMIL-STD-462Electromagnetic Interference Characteristics,Measurements forMIL-STD-883Test Methods and Procedures for Micro-electronicsMIL-STD-701List of Standard Semiconductor DevicesSAE AS1145 Revision B-3-3.GENERAL REQU

14、IREMENTS:3.1Function:The temperature monitor system covered by this specification shall provide a means of measuring brake temperature and conveying information based on this measurement to the pilot and/or flight engineer.Three areas of information are important.(a)Very high temperature,indicating

15、overheated brake conditions exist which may cause the fuse plugs to blow,or necessitate a tire,wheel,and brake inspection at the ramp.This condition may be caused by severe usage or excessive drag.(b)Moderate temperature,indicating that brakes contain energy levels which do not leave sufficient capa

16、city to perform an R.T.O.Under this condition,take-off should not be attempted.This condition can exist due to normal braking or slightly dragging brake.(c)Temperature Display.In the event that the pilot would desire to evaluate the brake thermal condition,the monitored temperature of each individua

17、l brake should be made available.This is most important if the indications for(a)or(b)are provided as warning indicator lamps.The display shall indicate over the range to which the sensor is exposed or as specified by the purchaser.The display shall indicate in degrees Celsius.3.1.1Design Objectives

18、:(a)Provide a high temperature indication when the temperature of any brake exceeds a predetermined safety threshold or reaches a temperature that may cause deterioration to the metallic chassis(as may be the case with a carbon heat sink brake).This temperature condition,if required by purchaser,can

19、 be displayed by a continuous lamp illumination or memory device indicating brake position and being resetable by ground/flight personnel.The temperature probe should be placed as close as possible to the heat source to provide minimum delay between the peak temperature of the heat sink and the peak

20、 temperature measured by the heat sensor element.(b)Provide an indication when,due to high temperature,the energy capacity of any one brake is below RTO requirements.It is recommended that it be supplied as a lamp indication.SAE AS1145 Revision B-4-3.1.1 (Continued):(c)The monitored temperature of t

21、he heat sink should be made available to the pilot and/or flight engineer at all times.The display can be of the needle indicator or of the digital readout type.If,at the purchasers option,it is desired to increase the brake maintenance utilization of the BTMS,consideration should be given to includ

22、e the capability of recording/displaying the highest brake temperature obtained during a stop with a resetable device.There are three configurations for displays that can be utilized for the BTMS requirements.(1)Single Display:In this configuration only one readout is provided.As used normally,this

23、readout continuously displays the temperature of the hottest brake.However,when utilizing the single display configuration,some provision should be made to select and display the temperature of each individual brake.(2)Multiple Brake Display:A display can be provided for more than one brake.For exam

24、ple,one display can be provided for each group on a strut.The readout should also display the temperature of the hottest brake in its group.Provisions should also be made to select and display the temperature of any brake of the group.(3)One Display for Each Brake:This configuration is the least des

25、irable of the three configurations.It is not recommended that this system be used on aircrafts with more than 4 brakes.Normally the highest temperature is all that is required.If the lowest temperature is also desired,the technique described in Design Objective(d)is recommended.(d)As an optional fea

26、ture a delta temperature(T)capability may be provided.The T lamp indicates that one brake temperature differs either higher or lower from the average brake temperature by an excessive amount.Illumination of this lamp will indicate a brake problem.A dragging brake will be hotter than the other brakes

27、.A brake that is defective and not providing its share of braking will be colder than the other brakes.Care must be exercised in selecting the brake groups for T,so that the lamp does not become a problem by giving false indications.Use of the brakes for steering could cause one side of the aircraft

28、 to have brakes much hotter than the other side,giving a false T indication.(e)For aircraft that include monitoring equipment for maintenance purposes,an output from the overheat circuit shall be provided.This output shall be disabled during“BITE”test.SAE AS1145 Revision B-5-3.1.1 (Continued):(f)Pro

29、vide a total system accuracy of 25 C(45 F)at an ambient temperature of 25 C(77 F).The system accuracy shall be within 50 C(90 F)over the operating temperature-40 C to+71 C(-40 F to 160 F).(g)The system shall be designed so that any shorts or opens in the sensor or sensor wiring will result in a zero

30、 brake temperature reading.3.1.1.1Self Test:System test provisions shall be included as an integral part of the BTMS design.Tests may be automatic or manual.Test operation or failure shall not reduce the system accuracy or response.The test shall,as a minimum,simulate a hot brake so that over temper

31、ature circuitry will also be evaluated as well as the analog or digital display.The test shall include evaluation of all brake channels and shall be capable of detecting sensor failures.Capability shall be included which will isolate a failure to a wheel channel.3.2Material and Workmanship:3.2.1Mate

32、rials:Materials shall be consistent with good commercial usage and suitable for the purpose intended.3.2.1.1Metals:All metals used in the construction of the BTMS shall be corrosion resistant unless suitably plated or treated to resist corrosion during stocking and normal service life.3.2.1.2Connect

33、ors:Connectors shall be selected in accordance with MIL-C-83723.The size of the connector shall be selected such that the number of pins will provide a minimum of 10%spares or 1 pin whichever is greater.3.2.1.3Electronic Components:All semiconductor microcircuits shall be screened to MIL-STD-883 Lev

34、el B.All discrete semiconductors shall be selected where possible from MIL-STD-701.All semiconductors shall be hermetically sealed and no plastic encapsulated semiconductors shall be used.3.2.2Workmanship:Workmanship and finish shall be in accordance with high grade aircraft accessory manufacturing

35、practice.3.3Identification:All major components shall be plainly and permanently marked for identification in accordance with Standard MIL-STD-130 or per requirements of the purchaser.3.3.1Units too small to carry the complete identification on the part shall be suitably tagged or stored in suitable

36、 containers.The unit,such as the sensor,shall carry as a minimum the name of the manufacturer,part number,and serial number.SAE AS1145 Revision B-6-3.4Design and Construction:Shall conform to the requirements specified herein.3.5System Components:The brake temperature monitor system consists of the

37、following major components.(a)Brake mounted sensor(s).(b)Reference junction(if applicable)or compensator.(c)Indicator unit,including meter(s)(or lights),required amplifiers,bridge,networks,level detectors,or other elements.Located for use by pilot and/or flight engineer.3.6Electrical Operation:Elect

38、rically operated components of the brake temperature monitor system shall operate satisfactorily on a voltage and power specified by the purchaser.Where a choice is given,an effort should be made to standardize by utilizing 28V DC aircraft supply.3.7Sensor:It shall be a design goal to replace,or ser

39、vice,the sensor assembly with minimum difficulty.If the sensor cable or tube is not permanently attached to the brake,the sensor assembly shall be replaceable without wheel or brake removal.Wiring to sensors shall be as continuous as possible.The sensors shall be capable of 50 actual removal/install

40、ation cycles on the associated aircraft wheel/brake unit when installed on the aircraft without sustaining cracks or damage to the sensor assembly.3.8Operating Conditions:3.8.1Non-Operating Temperatures:All system components shall be designed and constructed to withstand,as a minimum,ambient tempera

41、tures from-54 C to 71 C(-65 F to 160 F),or the operating temperatures,whichever are more severe.SAE AS1145 Revision B-7-3.8.2Operating Temperatures:The system components shall be designed and constructed for operation at the following temperatures:(a)Indicator unit shall be designed to operate over

42、temperature extremes of-40 C to 71 C(-40 F to 160 F).(b)Reference junction or compensator(unless part of the indicator assembly)shall be designed to operate within the temperature zone dictated by its location.These temperatures shall be supplied by the purchaser but not less than-54 C to 71 C(-65 F

43、 to 160 F).(c)Sensor assembly shall be designed and constructed to operate over a temperature range consistent with its location within the brake.Temperature exposure for each part of the assembly to be specified by the purchaser.As a minimum the sensor shall be capable of operating in the temperatu

44、re range of-54 C to 1093 C(-65 F to 2000 F).3.8.3Other Environmental Conditions:Sensor reference junction or compensator,cables and connectors shall remain functional after exposure to hydraulic or aircraft cleaning fluids and lubricants,aircraft fuels as well as the environmental requirements liste

45、d in paragraph 4.3.All conduits which protect cable runs on landing gear shall be environmentally sealed or provided with drain holes at their lowest point.3.9Interchangeability:All major components containing the same part number shall be directly interchangeable with no adjustment.4.QUALIFICATION:

46、4.1Sensor:4.1.1Visual Inspection:Inspect for good workmanship,absence of sharp edges obvious defects and for compliance with Sections 3.2 and 3.3.4.1.2Accuracy:The output of the sensor unit including the cold junction monitoring circuit(if a thermocouple is used)shall not vary from sensor to sensor

47、more than 5 C(9 F)from0 C to 500 C(32 F to 932 F).The plot of the sensor output versus temperature between 0 and 500 C(0 and 932 F)shall not vary from a straight line curve more than 5 C(9 F)below the overheat threshold temperature and not more than 20 C(36 F)for temperatures above the overheat thre

48、shold temperature.The overheat threshold temperature shall be used as the mid point calibration temperature for the indicator unit electronics.SAE AS1145 Revision B-8-4.1.3Environmental Tests:4.1.3.1Humidity Test:Test in accordance with Method 507,Procedure I,MIL-STD-810.Dry connector area with air

49、blast and test per 4.1.2 and 4.1.6 within one hour.4.1.3.2Fungus Test:This test shall be per Method 508 of MIL-STD-810.Unit need not operate during test.Test per 4.1.6 after test is completed.Vendor supplied affidavits that all materials used in components contain no nutrients to fungus are acceptab

50、le in lieu of fungus test.4.1.3.3Salt Spray Test:Test per Method 509,Procedure I,MIL-STD-810,except that the duration of test shall not be less than 24 hours.Rinse connector end with tap water and dry with air blast.Test per 4.1.2 and 4.1.6 within one hour.Inspect and test per 4.1.2 and 4.1.6 again