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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 entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefr
2、om, 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) 776-0243 TO PLACE A DOCU
3、MENT ORDER: (724) 776-4970 FAX: (724) 776-0790 SAE WEB ADDRESS http:/www.sae.org Copyright 1999 Society of Automotive Engineers, Inc. All rights reserved.Printed in U.S.A. SURFACE VEHICLE 400 Commonwealth Drive, Warrendale, PA 15096-0001 STANDARD Submitted for recognition as an American National Sta
4、ndard J2430 ISSUED AUG1999 Issued1999-08 Dynamometer Effectiveness Characterization Test for Passenger Car and Light Truck Brake Friction Products 1.Scope 1.1This SAE Recommended Practice establishes an inertia dynamometer test procedure, using exemplar caliper disc or drum brakes, to characterize t
5、he effectiveness of brake friction products for passenger cars and light trucks, up to and including 3500 kg GVW. SAE J2430 provides a method of characterizing friction material effectiveness, using vehicle specific brake hardware and test conditions that approximate those for U.S. mandated new vehi
6、cle brake tests. 1.2RationaleSAE J2430 is an improvement over SAE J661/J866 as a friction material effectiveness characterization test of replacement brake linings. SAE J661 uses a one-inch square sample running against a large drum and is known to have shortcomings for characterizing the vehicle pe
7、rformance of different types of automotive brake linings. 1.2.1SAE J2430 simulates certain sections of FMVSS 135. SAE J2430 is based on the controlled testing of unused friction materials against a new drum or rotor, using a prescribed set of test conditions that approximate those on a vehicle using
8、 the exemplar brakes. The FMVSS 135 vehicle test procedure emphasizes rapid braking from different speeds and includes a brake fade section. 1.2.2Interactive conditioning between brakes occurs during vehicle braking. These interactions can affect work history for both front and rear brakes with a hi
9、gher relative magnitude for rears. Variations in work history are known to cause variations in effectiveness. Also, it is recognized that brake effectiveness values can be influenced by brake and vehicle design, as well as by friction material characteristics. For the previous reasons, material effe
10、ctiveness comparisons using SAE J2430, should be based on testing with the same vehicle relevant brake and test conditions. 1.2.3SAE J2430 is not intended to characterize all aspects of friction material effectiveness, such as light duty performance, environmental sensitivity, or effectiveness drift
11、 after extended service. Also, SAE J2430 is not intended to provide a reliable characterization of lining wear, noise, or drum/rotor compatibility in typical customer service vehicle usage. 1.2.4SAE J2430 uses new, original equipment drums or rotors of prescribed chemistry, microstructure, and dimen
12、sions. Friction materials which require or use a unique mating surface may not be properly characterized by this test procedure. SAE J2430 Issued AUG1999 -2- 1.3Test FeaturesBrake effectiveness is reported as REGRESSED SPECIFIC TORQUE for ramp applications and as AVERAGE SPECIFIC TORQUE for torque a
13、nd pressure controlled applications. 1.4Test ApplicationBrake effectiveness values calculated from SAE J2430 may be used to aid in the selection of replacement friction materials for automotive disc and drum brakes that are similar in design and usage to that of the exemplar brake. 2.References 2.1A
14、pplicable PublicationsThe following publications form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest version of SAE publications shall apply. 2.1.1SAE PUBLICATIONSAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001. SAE J661Brake
15、 Lining Quality Control Test Procedure SAE J866Friction Coefficient Identification System for Brake Lining SAE J2115Brake Performance and Wear Test Code Commercial Vehicle Inertia Dynamometer 2.1.2FMVSS PUBLICATIONSAvailable from the Superintendent of Documents, U.S. Government Printing Office, Wash
16、ington, DC 20402. FMVSS 116 FMVSS 135 2.2Related PublicationThe following publication is provided for information purposes only and is not a required part of this document. 2.2.1SAE PUBLICATIONAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001. SAE J1652Dynamometer Effectiveness C
17、haracterization Test for Passenger Car and Light Truck Caliper Disc Brake Friction Materials 3.Test Preparation 3.1Dynamometer ConfigurationSAE J2430 is to be run on an inertia dynamometer with the following minimum capabilities: 3.1.1Variable speed drive system with speed resolution to 1 rpm and ca
18、librated to 0.5% accuracy at 160 km/h. The drive should have the capability to accelerate the required inertia from 0 to 1500 rpm in 20 s. 3.1.2Incremental inertia discs to simulate specified brake inertia within 2 kg*m2. 3.1.2.1Specified brake inertia values are determined from in-stop torque/dista
19、nce calculations as outlined in Appendix A. 3.1.3Test brake station, fully enclosed in an air duct of sufficient size to accept the brake hardware and meet brake cooling specifications. 3.1.3.1For caliper disc brakes, the brake test fixture is constructed from a vehicle knuckle, caliper, and rotor t
20、hat meet original equipment specifications. An adapter attaches the knuckle to the dynamometer tailstock. SAE J2430 Issued AUG1999 -3- 3.1.3.2For drum brakes, the test brake is constructed from a brake fixture, backing plate, and drum that meet original equipment specifications. A stub axle and adap
21、ter attach the backing plate to the dynamometer tailstock. A wheel or wheel section may be included to increase brake stiffness or assist in meeting the brake cooling rate. 3.1.4A pressure transducer, accurate to within 0.5% of the reading and calibrated over the range from 300 to 14 000 kPa. 3.1.4.
22、1The pressure transducer is mounted just outside the air duct to minimize transducer thermal drift. A short (150 mm) brake line connects the transducer to the brake. (7.1)1 3.1.4.2For disc brakes, a pressure connection is made at the piston centerline on the back of the caliper, or at the caliper bl
23、eed screw to measure output pressure. 3.1.4.3For drum brakes, a pressure connection is made through a T adapter at the wheel cylinder bleed screw. 3.1.5A tailstock section and load cell connected to the test brake. Load cell is calibrated over the required range and measures brake torque with an acc
24、uracy of 0.5% at a torque corresponding to 1.0 g deceleration 3.1.6A closed loop servo system to control brake applications under specified conditions. a. Servo system capabilities include: 1.Linear pressure rise rate, over the specified range from 300 kPa through 95% of maximum pressure for the app
25、lications. For certain rear brakes, the pressure rise rate may be bilinear with pre- and post- knee slope that simulate vehicle specific proportioning valve characteristics. 2.Torque rise rate during ramp, free of inflection points other than those due to friction material characteristics, or to the
26、 programmed change in pressure rise rate, over the range from 50 Nm through 95% of maximum torque during the ramp portion of a brake application. 3.Not more than 5% torque or pressure over-shoot beyond specified preset level. 4.For torque and pressure control applications, transition from ramp contr
27、ol to sustained torque or pressure control, should be within +0, 3% of the specified sustained level. 5.Maintain an average sustained torque or pressure within 1% of the specified level. The range of 100 Hz torque values during the sustained portion of a torque control application should not exceed
28、50 Nm. 3.1.7Automated and integrated temperature control and data acquisition system. Calibrated to 1% at 500 C. 3.1.8A negative pressure, closed loop brake cooling system to maintain required cooling air velocity and temperature during and between each test section. A metal screen with nominal 6 to
29、 12 mm openings in the air duct, about 30 cm upstream of the brake, is recommended to improve air flow uniformity. 3.1.9An automated and integrated data acquisition system to record specified data. 1.Section 7 provides supplementary Test Notes. SAE J2430 Issued AUG1999 -4- 3.1.10 The frequency conte
30、nt of the information gathered in SAE J2430 is typically less than 15 Hz. Appropriate analog and digital filtering is necessary to insure good analog amplitude quantification. Therefore, minimum analog filtering with a 200 Hz, low pass, two-pole filter is required along with a minimum digital sampli
31、ng rate of 400 Hz for speed, torque, and pressure data. This data is digitally filtered in a manner that does not insert a relative phase shift between measured channels. All instantaneous data is reported as 100 Hz filtered values that meet the previous criteria. 3.2Data Processing SystemAn automat
32、ed data processing system is recommended to carry out specified calculations, including least squares regression analysis and effective inertia, as well as distance averaged torque and pressure values. 3.3Drum Brake ComponentsUse only original equipment brake hardware and component parts that meet a
33、ll applicable vehicle manufacturers specifications. 3.3.1BRAKE DRUMFor each test, use a new, original equipment drum. Verify that test drum meets vehicle manufacturers specifications for inside diameter, ovality, and surface finish. (7.2) Test drum should be free of nicks, corrosion, or surface cont
34、amination. Do not grind or lathe cut inside diameter before use unless drum is outside vehicle manufacturers specifications. 3.3.1.1Install a plug type copper thermocouple in the drum. Drill 3.0 mm hole through drum at the center of lining rubbing track. Debur hole and mount thermocouple 1.0 mm belo
35、w drum wear surface. Prepare thermocouple with #24 AWG “J” type thermocouple wire (solid, glass on glass) or equivalent, at least 60 cm long. Use 3.18 mm silver soldered, copper thermocouple plug per SAE J2115. It is recommended that plug be formed slightly out of round to insure a secure fit into t
36、he drilled hole. 3.3.1.2Just prior to running SAE J2430, thoroughly clean drum surface with isopropyl alcohol and paper towels. (7.3) 3.3.2LINED BRAKE SHOES 3.3.2.1Aftermarket lined brake shoes are supplied a minimum of 1 mm over original equipment specified thickness to allow for final friction mat
37、erial grind based on actual drum diameter. Original equipment lined brake shoes are tested as manufactured. 3.3.2.2Use bonded or riveted lined brake shoes which correspond to commercial products. 3.3.2.3Use new original equipment or equivalent brake shoes. 3.3.2.4Locate friction material on shoes pe
38、r original equipment specifications. Assemble linings parallel to shoe table with no overhang. Heel and toe lining chamfer is optional, but should be consistent with commercial products. 3.3.2.5Using an appropriate fixture and shoe grinder, final grind lined shoes to 0.45 to 0.55 mm under the averag
39、e inside drum diameter to insure consistent contact at the horizontal midpoint of lining and avoid heel/toe contact. See 7.2. 3.3.2.6Install lining thermocouples. Drill 3.0 mm holes through each shoe and lining 1.0 mm off the centerline at the horizontal center of each shoe. Use #24 AWG “J” type the
40、rmocouple wire (solid, glass on glass) or equivalent, at least 60 cm long. Use 3.18 mm X 3.18 mm silver soldered, copper thermocouple plug per SAE J2115. Mount thermocouple 1.5 mm below lining wear surface. It is recommended that plugs be formed slightly out of round to insure a secure fit into the
41、drilled hole. Run thermocouple wire through backing plate side of the shoe web to the tailstock connector. SAE J2430 Issued AUG1999 -5- 3.3.3WHEEL CYLINDERUse an original equipment wheel cylinder. Inspect prior to each test and replace wheel cylinder if there is any evidence of leaks or thermal abus
42、e. 3.3.4SPRINGS, CLIPS, AND PINS 3.3.4.1Use new, original equipment springs, clips, and pins for each test. 3.3.5BACKING PLATEInspect backing plate prior to each test. Replace if there is any evidence of wear or bending. 3.3.6FIXTURE ASSEMBLY AND ALIGNMENTUsing a dial indicator mounted on the drive
43、shaft, align dynamometer tailstock shaft to driveshaft before mounting brake fixture or drum. Alignment should be square and concentric with 0.1 mm maximum TIR. Mount stub axle fixture with backing plate to tailstock flange without shoes. Locate backing plate such that wheel cylinder axis is horizon
44、tal. Torque backing plate mounting bolts per manufacturers recommendation. Use dial indicator mounted on driveshaft to indicate drum pilot hole concentricity and flange squareness with 0.1 mm maximum TIR. With dial indicator on driveshaft, indicate squareness of backing plate shoe support platforms.
45、 TIR should not exceed 0.25 mm over all shoe support platforms. 3.3.6.1Measure and report mounted drum run-out by drilling a small hole in backing plate for dial indicator. Verify that drum is on center with driver. Re-index or replace drum if mounted drum run-out exceeds 0.07 mm. 3.3.6.2Assemble sh
46、oes, springs, and parking brake lever, without a cable, to backing plate. 3.3.6.3Cover backing plate cable hole to reduce air flow inside brake. 3.3.7BRAKE ASSEMBLYAssemble brake per manufacturers recommendations. Connect lining thermocouple wires to tailstock connectors and drum thermocouple wire t
47、o slip ring. Use average drum diameter from 3.3.1 and manually adjust shoes with star wheel to a cage diameter on horizontal line of brake to 0.45 to 0.55 mm under drum diameter. 3.3.7.1Close brake and manually rotate drum to verify minimal rubbing torque. 3.3.7.2Thoroughly bleed brake at wheel cyli
48、nder T valve and at master cylinder. 3.4Disc Brake Components 3.4.1BRAKE ROTORUse a new, original equipment rotor for each test. Rotors should not be lathe cut or ground prior to use and should be free of surface corrosion, contamination, or nicks. Verify that test rotor meets vehicle manufacturers
49、specifications for run-out, and surface finish. 3.4.1.1Use #24 AWG “J” type thermocouple wire (solid glass on glass), or equivalent, at least 60 cm long to connect rotor thermocouple to tailstock slip ring. Use 3.18 mm OD x 3.18 mm long silver soldered copper plug thermocouple per SAE J2115. It is recommended that plugs be formed slightly out of round to insure a secure fit into drilled holes. For a vented rotor, drill a 3.0 mm hole through the inner pad rotor face. Locate hole between ribs at the center point of rubbing track. Debur hole and mount therm