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 entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2014 SAE International All rights reserved. No part of this pu
3、blication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970
4、 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J1789_201408SURFACE VEHICLESTANDARDJ1789REAF.AUG2014Issued 2002-08 Reaffirmed 2014-
5、08 Superseding J1789 SEP2007Self-Propelled Sweepers and Scrubbers Braking Performance RATIONALEJ1789 has been reaffirmed to comply with the SAE five-year review policy. 1. ScopeThis SAE Standard applies to self-propelled, rider operated, sweepers and scrubbers as defined inSAE J2130 with maximum mac
6、hine level surface speeds up to 32 km/h. Machines capable of speeds equal toand greater than 32 km/h are not covered by this document.1.1 Purpose1.1.1 To provide minimum performance criteria for service braking systems, secondary stopping systems andparking brake systems for self-propelled street sw
7、eepers, industrial sweepers and industrial scrubbers.1.1.2 To provide test criteria by which machine braking system performance may be verified.1.2 RationaleThis document has been reaffirmed to comply with the SAE 5-Year Review policy.2. References2.1 Applicable PublicationsThe following standards f
8、orm a part of the specification to the extent specifiedherein. Unless otherwise indicated, the latest revision of the publications shall apply.2.1.1 SAE PUBLICATIONAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel:877-606-7323 (inside USA and Canada) or 724-776-4970 (outside
9、 USA), www.sae.org.SAE J2130Self-Propelled Sweepers2.1.2 ISO PUBLICATIONSAvailable from ANSI, 25 West 43rd Street, New York, NY 10036-8002, Tel:212-642-4900, www.ansi.org.ISO 6014:1986Earth-moving machineryDetermination of ground speedISO 6016:1982Earth-moving machineryMethods of measuring the masse
10、s of whole machines, theirequipment and componentsISO 9248:1992Earth-moving machineryUnits for dimensions, performance and capacities, and theirmeasurement accuracies3. Definitions3.1 Self-Propelled Sweepers and ScrubbersMachines for sweeping and scrubbing floors and roads asdefined in SAE J2130.3.2
11、 Brake SystemsAll the components which combine together to stop and/or hold the machine. Such systemsinclude the control(s), means of brake actuation and the brake(s).3.3 Service Brake SystemPrimary system used for stopping and holding the machine.3.4 Secondary Brake SystemSystem used for stopping t
12、he machine in the event of any single failure in theservice brake system.3.5 Parking Brake SystemSystem used to hold a stopped machine in a stationary position.3.6 Brake System Components3.6.1 BRAKE CONTROL(S)Component(s) directly activated by the operator to cause a force to be transmitted tothe br
13、ake(s).3.6.2 BRAKE ACTUATION SYSTEMAll components between the control(s) and the brake(s) which connect themfunctionally.3.6.3 BRAKE(S)Components which directly apply a force to oppose movement of the machine. Brakes may, forexample, be of friction, electrical, hydrostatic or other fluid types.3.7 C
14、ommon ComponentsComponents that perform a function in two or more brake systems.3.8 Machine MassMass of the machine that includes the heaviest combination of manufacturer approvedequipment and components (i.e., cab, protective structures, etc.), rated payload, an operator of 75 kg, full fuel,lubrica
15、ting, hydraulic and cooling systems. The machine mass and payload distribution shall be according tothe manufacturers specification.3.9 Stopping Distance, sDistance travelled by the machine from the point on the test course at which themachine brake control is initially actuated to the point where t
16、he machine comes to a complete stop.3.10 BurnishProcedure to condition the frictional surfaces of the machine brake(s).3.11 Brake System PressureFluid pressure available to the brake control.3.12 Brake Application PressureFluid pressure measured at the brake.3.13 Modulated BrakingCapability to conti
17、nuously and progressively increase and decrease the braking force byoperation of the brake control.3.14 Test CourseSurface upon which the test is carried out.3.15 Cold BrakesExpression designating brakes where;The brakes have not been actuated in the previous 1 hour,orThe brakes have been cooled to
18、100 C or less when measured on the brake disk or on the outside of thebrake drum,orSAE INTERNATIONAL J1789 Reaffirmed AUG2014 Page 2 of 7_ In the case of totally enclosed brakes, including oil-immersed brakes, the temperature measured on theoutside of the housing closest to the brake is below 50 C o
19、r within the manufacturers specifications.3.16 Maximum Machine Level Surface Speed (V)Machine speed in kilometers per hour, determined inaccordance with ISO 6014.4. Instrument AccuracyTest instruments used to carry out the required measurements shall conform to therequirements of ISO 9248.5. General
20、 RequirementsThe following requirements for brake systems apply to all machines described inSection 1.5.1 Required Brake Systems5.1.1 The machine shall have the following brake systems;a. A service brake system.b. A secondary brake system.c. A parking brake system.5.1.2 No brake system shall contain
21、 a disconnecting device such as a clutch or a shiftable gearbox that allows thebrake(s) to be disabled.5.1.3 A power source disconnect designed for cold weather starting which also disables a brake system shallrequire application of the parking brake prior to disconnection.5.2 Common ComponentsBrake
22、 systems may use common components. However, a failure of any singlecomponent other than a tire, or a failure of any single common component shall not reduce the effectiveness ofthe machines stopping capability to less than the secondary performance defined in 7.6.2.4, with oneexception: a common co
23、ntrol (lever, pedal, switch, etc.) may be used to actuate combined service andsecondary brake systems provided that another dynamic braking capability is provided that will stop themachine within 120% of the dynamic stopping distances shown for the secondary brakes in 7.6.2.4. Thisbraking capability
24、 may be applied automatically and without modulation.5.3 Service Brake System5.3.1 All machines shall meet the service brake performance requirements of 7.5 and 7.6.2.3.5.3.2 If other systems are provided with power from the service brake system, any failure in these systems shall beconsidered to be
25、 the same as a failure in the service brake system.5.3.3 All machines shall have brakes of equal nominal capacity rating applicable to each wheel of at least one axle.5.3.4 The service brake system shall be of the modulated type as defined in 3.13.5.4 Secondary Brake System5.4.1 All machines shall m
26、eet the secondary brake performance requirements of 7.6.2.4.5.5 Parking Brake System5.5.1 All machines shall meet the parking brake requirements of 7.5.SAE INTERNATIONAL J1789 Reaffirmed AUG2014 Page 3 of 7_ 5.5.2 After being applied, this system shall not depend on an exhaustible energy source. The
27、 parking brakesystem may use common components with other brake systems provided the requirements of 7.5 are met.5.6 Warning Device for Stored Energy SourcesIf stored energy is used for the service brake system, thatsystem shall be equipped with a warning device which is activated before the system
28、energy drops below 50%of the maximum operating energy level specified by the manufacturer or the level required to meet thesecondary brake performance requirements, whichever level is higher.The device shall readily attract the operators attention by providing a continuous visible and/or audiblewarn
29、ing. Gauges indicating pressure or vacuum do not meet this requirement.6. Test Conditions6.1 The manufacturers safety precautions and correct operating procedures shall be observed while carrying outperformance tests.6.2 The test course surface shall be clean, dry, level asphalt, brushed concrete, o
30、r equivalent. The test course shallbe of sufficient length to permit a stabilized travel speed of the machine before application of the brakes. Thebraking surface shall not be of a slope greater than 1% in the direction of travel, or more than 3% slope at rightangles to the direction of travel.6.3 T
31、he machine shall be loaded to the maximum machine mass as per 3.8.6.4 All parameters relating to braking systems performance shall be within the machine manufacturersspecifications, i.e., tire size and pressure, brake adjustment, warning actuation point, etc. All brake systempressures shall be withi
32、n the manufacturers specification range. No manual adjustment(s) shall be made to thebraking system during any single test.6.5 When the machines transmission provides a selection of gear ratios, the stopping tests shall be conductedwith the transmission in the gear corresponding to the test speed sp
33、ecified. The power train may bedisengaged prior to completing the stop.6.6 Payload sweeping hoppers and debris containers shall be positioned in the transport (i.e., lowered) positionduring the tests.6.7 Burnishing or conditioning of the brakes before testing is permissible. The burnishing procedure
34、 shall beindicated in the operators and/or maintenance manual for the machine and shall be verified by consultationwith the machine manufacturer.6.8 Immediately prior to the tests the machine shall be operated until the machine fluids, i.e., engine andtransmission oils, are at normal operating tempe
35、rature as specified by the manufacturer.6.9 Machine test speed shall be that speed measured immediately prior to the brake control being applied.7. Performance Requirements7.1 Brake System Controls7.1.1 The control forces to meet the required brake performance for the systems defined in 7.5, 7.6.2.3
36、, and7.6.2.4 shall not exceed the values given in Table 1.SAE INTERNATIONAL J1789 Reaffirmed AUG2014 Page 4 of 7_ 7.1.2 All brake system controls shall be capable of being applied by a person seated in the drivers seat. Thesecondary and parking brake system(s) control(s) shall be arranged so that th
37、ey cannot be released oncethey have been applied unless they can be immediately reapplied.7.2 Service Brake System Recovery Capacity (Stored Energy System)The engine speed control shall beset to obtain maximum engine rotational speed (r/min) or frequency (min1). The brake application pressureshall b
38、e measured near a brake. The service brake system shall be capable of delivering at least 70% of thepressure measured during the first brake application after the service brakes have been fully applied 12 timesat the rate of 6 applications per minute.Calculate the percentage of the service brake sys
39、tem stored energy after the brake application test calculatedfrom the following formula:(Eq. 1)where:p is the residual pressure as a percentage,p1is the brake application pressure during the first brake application,p2is the lowest brake application pressure measured during subsequent brake applicati
40、ons;7.3 Secondary Brake System Capacity (Stored Energy System)Where stored energy reservoir(s) for theservice brake is (are) used to supply the energy for the secondary brake, the capacity of the reservoir(s), withthe energy source disconnected and the machine stationary, shall maintain sufficient e
41、nergy after five fullservice brake applications to meet the secondary brake requirements specified in 7.6.2.4.7.4 Warning Device for Stored Energy SystemIf the service brake system energy is reduced by any means, awarning device (see 5.6) shall activate before the system energy drops below the great
42、er of 50% of themanufacturers specified maximum operating energy level, or the stored energy level required to meet thesecondary brake requirements specified in 7.6.2.4. The warning device shall activate prior to an automaticapplication of the secondary brake system.7.5 Holding PerformanceAll machin
43、es shall be tested in both the forward and reverse directions in accordancewith the machine conditions as specified in Section 6.The service brake and park brake system shall be capable of holding the machine on a slope with the powertrain disengaged (unless a hydrostatic transmission is used for th
44、e service brake system) as given in Table 2:TABLE 1MAXIMUM FORCE LEVELS FOR BRAKE SYSTEM CONTROLSFOR PERFORMANCE TESTSType of Control Maximum Force to be AppliedFoot pedal (leg control) 600 NFoot treadle (ankle control) 350 NHand grasp (upwards) 400 NHand grasp (downwards, sideways, fore-aft) 300 NF
45、inger grasp (flip levers b. The type of machine;c. The make of machine;d. The model and serial number of the machine;e. The condition of the brake system (for example, new, in operation for 10 hours, etc.);f. The mass, in kilograms, and the axle loads, in newtons, of the machine as tested;g. The man
46、ufacturers approved maximum machine mass, in kilograms, and the axle loads, in newtons;h. The size, ply rating, tread pattern and tire pressures, in megapascals;i. A description of the brakes (for example, disc or drum, hand or foot control);j. The type of brake system (for example, mechanical or hy
47、draulic);k. The surface of the test course (for example, asphalt, concrete or soil);l. The longitudinal and cross gradients of the test course;m. The results of all stopping and holding tests;n. Percentage of the service brake system stored energy after the brake application test, calculated asspeci
48、fied in 7.2;o. The force levels applied to the controls (see 7.1.1);p. The maximum level surface speed in kilometers per hour;q. The secondary brake system capacity for a stored energy system (see 7.3).PREPARED BY THE SAE OPERATOR PROTECTION TECHNICAL COMMITTEE SC2BRAKINGSAE INTERNATIONAL J1789 Reaffirmed AUG2014 Page 7 of 7_
