FORD FLTM EU-BZ 053-2-2001 FRICTION ASSESSMENT SCREENING TEST (FAST) BRAKE AND CLUTCH PROCEDURES.pdf

1、 FORD LABORATORY TEST METHOD EU-BZ 053-02 Date Action Revisions 2001 04 30 Revised Editorial no technical change A. Cockman 1994 02 28 Printed copies are uncontrolled Page 1 of 7 Copyright 2001, Ford Global Technologies, Inc. FRICTION ASSESSMENT SCREENING TEST (FAST) BRAKE AND CLUTCH PROCEDURES Appl

2、ication These procedures are used to establish the friction and wear properties of clutch facing materials on a standard test machine. Method A: Standard Clutch Procedure Method B: Heavy Duty Clutch Procedure Method C: Light Duty Brake Procedure Method D: Heavy Duty Brake Procedure Method E: Severe

3、Duty Brake Procedure Apparatus 1. Standard Ford, Dearborn developed, FAST machine (see Figure 1). Source: Bush Manufacturing Clawson, Michigan U.S.A. 2. T-Y recorder, with a 90 minute T axis. Source: Bush Manufacturing 3. Test Discs Cast iron discs, 180 mm diameter x 38 mm thickness of the following

4、 specification: Total Carbon 3.35 - 3.65 Combined Carbon 0.60 - 0.80 desired Manganese 0.60 - 0.90 Silicon 1.80 - 2.10 Phosphorus 0.20 max Sulphur 0.12 max Chromium (Optional) 0.05 - 0.15 Brinell Hardness 170 - 225 FORD LABORATORY TEST METHOD EU-BZ 053-02 Page 2 of 7 Copyright 2001, Ford Global Tech

5、nologies, Inc. Carbon-Silicon ratio must be adjusted to maintain physical properties and microstructure. The microstructure shall consist of flake graphite evenly distributed in a matrix of pearlite. Free ferrite, steadite or cementite not desired. Source: Mintex Limited Cleckheaton, Yorkshire 4. La

6、boratory Balance - capable of weighing to 0.001 g. 5. Desiccator - silica gel desiccant. 6. Files for sample preparation. Materials 1. Emery paper 150, 220, 320 grit for preparing discs. 2. Acetone, technical grade. Conditioning and Test Conditions All test values indicated herein are based on mater

7、ial conditioned in a controlled atmosphere of 23 +/- 2 C and 50 +/- 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions unless otherwise specified. Procedure 1. Machine settings are checked as follows: 1.1 Disc Run-out Test disc run-out measured at the

8、outer edge of the working surface under a no-load condition must not exceed 0.06 mm TIR. 1.2 Tension Rod Parallelism The clamping load tension rod must be parallel to the test disc axis. This alignment is checked by setting the controls as follows: (a) Pump on FORD LABORATORY TEST METHOD EU-BZ 053-0

9、2 Page 3 of 7 Copyright 2001, Ford Global Technologies, Inc. (b) Drive motor off (c) Load arm in test position check parallelism of arm and disc face in accordance with the FAST machine manual. (d) Transducer selector valve set to record friction pressure (equal to weight of load arm). (e) Load valv

10、e E in closed position. When load valve E is opened, the recorder trace must not deflect more than +/- 0.01 N/mm2 (friction pressure). 1.3 Hydraulic Control System Accuracy The hydraulic control system must be capable of maintaining friction pressure within 0.01 N/mm2 of the value in Table 1 for the

11、 specified clamping pressure. This ability is checked by pushing up and down on the load arm during a test run until the clamping pressure ranges indicated on the clamping pressure gauge are in accordance with Table 1. The transducer valve is set to record friction pressure during the check. 1.4 Wea

12、r Stop The wear stop set screw must be adjusted to provide a 0.1 to 0.2 mm clearance between the load arm and test disc. 1.5 Test Room The test atmosphere must be oil free. The room temperature must be 18 - 32 C with a humidity of less than 90 %. Record actual room temperature on the test trace. 2.

13、Test Procedure 2.1 Sample Preparation Clutch facing samples shall not include rivet holes and the centre line of the sample shall be a radius of the disc. Disc brake pad samples shall be taken from the central area of the pad and the surface to be tested should remain untouched. Drum brake lining su

14、rfaces should be filed flat and the sample taken from the central area of the lining. The finished dimensions must be as follows: FORD LABORATORY TEST METHOD EU-BZ 053-02 Page 4 of 7 Copyright 2001, Ford Global Technologies, Inc. Table 1 Procedure A B C D E Length 25.3 25.5 12.6 12.8 Width 25.3 25.4

15、 12.6 12.8 12.6 12.8 Thickness 3.1 3.5 Identify the non-test surface by marking (e.g. Sample A). Remove any burrs from test surface. The specimen to be flat and parallel within 0.03 mm. The sample is weighed after storing in a desiccator for a minimum of 24 h and the dimensions recorded. 2.2 Disc Pr

16、eparation New, freshly machined, or contaminated test discs must be cleaned in a vapour degreaser to remove all traces of oil. Prior to each test, the disc surface must be conditioned as follows: With the disc mounted on the test machine, drive motor on, polish the test surface with a 320* grit abra

17、sive cloth (solidly backed and flat to remove all traces of organic coatings and most scoring grooves until a 0.125 - 0.250 micrometre finish is obtained. A 150* grit may be used for initial polishing. Clean the finished surface with acetone until the wipers remain essentially clean. Do not touch th

18、e finished surface. *Aluminum oxide or silicon carbide cloth backed abrasive only. Never use rouge type abrasive or crocus. 2.3 Sample Position Place the sample in the testing position and visually check the sample surface parallelism with the test disc. If necessary loosen the locking bolts and adj

19、ust the upper mounting plate to align the sample load arm and the disc. The heavy duty clutch sample is mounted vertically with the centre line of the major axis 68.6 mm from the centre of the disc. FORD LABORATORY TEST METHOD EU-BZ 053-02 Page 5 of 7 Copyright 2001, Ford Global Technologies, Inc. 2

20、.4 Test Run Close the clamping valve damping control C and open the friction valve damping control B approximately one turn. Calibrate the instrumentation. With a test sample in place turn the pump on, the selector valve to record friction pressure and the specimen loading valve E to the off positio

21、n. Slacken the tension rod nut so there is no pressure between the sample and the disc and note the arm weight recorded on the graph (start and stop the drive motor to check there is no change in the arm weight on the graph). Tighten the tension rod nut, check the load arm is parallel with the disc

22、and start the drive motor. Turn the load valve E parallel to the disc face to load the sample. Set the load adjustment screw to friction pressure in Table 1, indicated by the recorder. (This does not include arm weight. The friction pressure should be above the recorded arm weight on the graph by th

23、e value in Table 2.) Lock the adjusting screw and unload the sample momentarily. Reload the sample, check and reset the friction pressure if necessary. Turn selector valve D to record clamping pressure on the graph. Continue running the sample until the test is completed. The mean friction pressure

24、during the run must remain within 0.01 N/mm2 of the test value. The friction pressure must be checked during a run, for a period of 30 s by turning the transducer selector valve D to record friction spool pressure. One 30 s record of friction pressure must be displayed on each test trace at 10 minut

25、es. After the conditioning test, the sample is cooled in a desiccator and weighed. The disc is cooled to below 60 C (preferably to 23 +/- 2 C). The characterisation test follows the same procedure except the test duration is 90 minutes. NB: Care should be taken between the 60 and 90 minute tests not

26、 to touch or contaminate the sample and disc mating surfaces. There is no conditioning test required for Procedure B, C, D, and E, only a single 60 or 90 minute test is performed. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is

27、responsible for determining proper use and handling in its facilities. FORD LABORATORY TEST METHOD EU-BZ 053-02 Page 6 of 7 Copyright 2001, Ford Global Technologies, Inc. FRICTION ASSESSMENT SCREENING TEST (FAST) CLUTCH PROCEDURES Table 2 Calculation Apparent Density This test is a determination of

28、a volume/weight relationship on the friction material. Test Procedure The specimen to be used for the FAST procedure is accurately weighed and its dimensions measured to the nearest 0.025 mm before the conditioning test. Apparent Density is calculated as follows: Density = W x 103 L1 x L2 x T Where:

29、 W = Weight of sample in g. L1 & L2 = Side dimensions in mm. T = Side thickness in mm. Calculation of Wear Rate 76 x 103 x (W o - WF) mm3 /MJ 2.685 AD x F x V x T Where: Wo = Sample weight before test - g. Wf = Sample weight after test - g. F = Friction load - N. V = Velocity = 7.01 m/s (Constant).

30、T = Test duration - hours. AD = Apparent Density as calculated above. Procedure A B C D E Friction Load, N 50.7 77.4 38.7 77.4 116.1 Friction Pressure N/mm2 0.357 +/- 0.01 0.552 +/- 0.01 0.276 +/- 0.01 0.552 +/- 0.01 0.827 +/- 0.01 Clamping Pressure Range, N/mm2 0 0.42 0 0.69 0 0.35 0 0.69 0 1.03 Te

31、st Duration, min Condition Characterisation 60 90 90 60 90 60 FORD LABORATORY TEST METHOD EU-BZ 053-02 Page 7 of 7 Copyright 2001, Ford Global Technologies, Inc. FRICTION ASSESSMENT SCREENING TEST (FAST) BRAKE AND CLUTCH PROCEDURES Figure 1 Schematic Diagram of Fash Test Methods A = Load control scr

32、ew B = Needle valve B (damping) C = Needle valve C (closed) D = Selector valve D E = Load dump valve E F = Clamping valve spool G = Friction valve spool H = Clamping assembly J = Tension rod K = Universal pivot L = Motor driven friction disc M = Test specimen N = Load arm P = Clamping pressure gauge Q = Friction pressure gauge R = Pump supply connection S = Clamping pressure to transducer