1、 FORD LABORATORY TEST METHOD BJ 152-01 Date Action Revisions 2001 07 25 Revised Editorial no technical change A. Cockman 1994 02 28 Printed copies are uncontrolled Page 1 of 7 Copyright 2001, Ford Global Technologies, Inc. PRESS FIT TEST TO DETERMINE THE COEFFICIENT OF FRICTION OF LUBRICANTS Applica
2、tion This method is used to ascertain the coefficient of friction by determining the film strength or load-carrying property of lubricants using mechanical testing equipment. Apparatus Required Compression Testing Machine Calibrated, with a load range 0 - 100 kN, a constant press (crosshead) speed o
3、f 15 mm/minute and an automatic recorder. Thickness Gauge With an indicating range of 0.04 mm and an accuracy of 0.2 micrometre. Source: C.E.J. Precision Gauges Ltd. C.E. Johansson & Co. GmbH 76 High Street North 6100 Darmstadt Dunstable Beds, U.K. Bleichstrasse 4, Postfach 529 or equivalent. Standa
4、rd Pins and Bushings (SAE 1117, case-hardened 0.60 +/- 0.05 mm deep to a Rockwell C 58-64) surfaces and ground to finish of 0.2 - 0.4 micrometre. CLA, rms, with an interference fit of 25 +/- 2 micrometre. Source: DOW Corning International Ltd. Firma Josef Wizeman & Co. Brussels 7 Stuttgart-Bad Canns
5、tatt 25 Rue de la Loi Quellenstrasse 7 Belgium West Germany or equivalent. FORD LABORATORY TEST METHOD BJ 152-01 Page 2 of 7 Copyright 2001, Ford Global Technologies, Inc. Materials Required Petroleum Naphtha M14J148A or U-MC 004-8004-01 CAUTION: Low flash point - Refer to Industrial Hygiene for hea
6、lth and safety comments. Plunger and Support Refer to Figure 1. Conditioning and Test Conditions All test values indicated herein are based on material 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 s
7、ame conditions unless otherwise specified. Procedure (Three specimens are required). 1. Clean a new test pin and bushing for one test by immersing in petroleum naphtha and rub with lint-free cloth. Rinse in second bath of petroleum naphtha and air dry. Repeat this cleaning process three times in tur
8、n. 2. Measure the initial bushing O.D. (A) to the nearest 1 micrometre. Mark a small circle on the surface of the bushing to identify the measuring point. 3. Apply the lubricant to be tested on the inside surface of the bushing and the outside surface of the pin. Use a soft hair brush to apply powde
9、rs or oils and a spatula for greases. 4. Press fit the pin into the bushing at the constant fixed press speed of 15 mm/minute. Bushing and pin must be in a vertical position. 5. Stop operation when the ground surface of pin has been completely enveloped by the ground surface of the bushing. 6. Durin
10、g test record load at which chatter begins, if any. 7. Record maximum press fit load (PL) and remove pin and bushing as a unit. 8. Measure the bushing O.D. (B) to the nearest 1 micrometre (and denote the location with a small circle) and calculate the expansion O.D. and the kinetic coefficient of fr
11、iction. (See evaluation, Page 3 and Table I). FORD LABORATORY TEST METHOD BJ 152-01 Page 3 of 7 Copyright 2001, Ford Global Technologies, Inc. 9. After a defined time as required in the applicable Engineering Material Specification record breakaway load and push pin out at a speed of 15 mm/ minute.
12、10. Measure bushing O.D. (C) and calculate O.D. contraction to the nearest 1 micrometre and the static coefficient of friction. (See evaluation, Page 3 and Table I). Evaluation Evaluate the kinetic coefficient of friction and the static coefficient of friction by using “Summary of Test Results on Pr
13、ess Fit Test“ and Table I. Determine the “Press Fit Pressure“ by using Table II. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities. FORD LABORATORY TEST METHOD
14、BJ 152-01 Page 4 of 7 Copyright 2001, Ford Global Technologies, Inc. PRESS FIT TEST TO DETERMINE THE COEFFICIENT OF FRICTION OF LUBRICANTS Summary of Test Results on Press Fit Test No. . . Supplier: Lubricant: Maximum Press Fit Load (kin) (PL) _ kN Chatter: _ yes _ no Initial Chatter Load _ kN Break
15、away Load (static) (BL) _ kN Dimensions of Bushing O.D. Initial (A) _ micrometre Kinetic Friction Static Friction Pin pushed in (B) _ micrometer Pin pushed out (C) _ micrometre Measured change in Dimension O.D. (B-A=EK) _ micrometer (B-C=ES) _ micrometre Load Correction Factor (K) (see Table I) kin
16、_ static _ Load corrected (PL x K) kin _ kN (BL x K) static _ kN Coefficient of Friction (micrometre) = Load corrected in kN 256 Kinetic Friction ( )_ Static Friction ( )_ Press fit pressure (PR) _ kN/k2 (see Table II - use EK for finding press fit pressure) Remarks: Date: _ Signature: _ FORD LABORA
17、TORY TEST METHOD BJ 152-01 Page 5 of 7 Copyright 2001, Ford Global Technologies, Inc. PRESS FIT TEST TO DETERMINE THE COEFFICIENT OF FRICTION OF LUBRICANTS Figure 1 FORD LABORATORY TEST METHOD BJ 152-01 Page 6 of 7 Copyright 2001, Ford Global Technologies, Inc. PRESS FIT TEST TO DETERMINE THE COEFFI
18、CIENT OF FRICTION OF LUBRICANTS Table I Measure Change in Dimension E (Micrometre) and Load Correction Factor K E K E K E K 10.16 2.250 17.02 1.343 23.88 0.957 10.42 2.195 17.27 1.324 24.13 0.947 10.67 2.143 17.53 1.304 24.38 0.938 10.92 2.093 17.78 1.286 24.64 0.928 11.17 2.045 18.03 1.268 24.89 0.
19、918 11.42 2.000 18.29 1.250 25.15 0.909 11.67 1.957 18.54 1.233 25.40 0.900 11.92 1.915 18.79 1.216 25.64 0.891 12.17 1.875 19.05 1.200 25.91 0.882 12.42 1.837 19.30 1.184 26.16 0.874 12.67 1.800 19.56 1.169 26.42 0.865 12.92 1.765 19.81 1.154 26.67 0.857 13.17 1.731 20.06 1.139 26.93 0.849 13.72 1.
20、667 20.57 1.111 27.43 0.833 13.97 1.636 20.83 1.098 27.69 0.826 14.22 1.607 21.08 1.084 27.94 0.818 14.47 1.579 21.34 1.071 28.19 0.811 14.73 1.552 21.59 1.059 28.45 0.804 14.98 1.525 21.84 1.047 28.70 0.796 15.24 1.500 22.10 1.034 28.96 0.789 15.49 1.475 22.35 1.023 29.12 0.783 15.75 1.452 22.61 1.
21、011 29.46 0.776 16.00 1.429 22.86 1.000 29.72 0.769 16.26 1.406 23.11 0.989 29.97 0.763 16.51 1.385 23.37 0.978 30.23 0.765 16.76 1.364 23.62 0.968 30.48 0.750 FORD LABORATORY TEST METHOD BJ 152-01 Page 7 of 7 Copyright 2001, Ford Global Technologies, Inc. PRESS FIT TEST TO DETERMINE THE COEFFICIENT
22、 OF FRICTION OF LUBRICANTS Table II Determination of Press Fit Pressure P in k/m2 Based on the Increase of Bush Diameter ED (micrometre) EK PR EK PR 17.78 809 00 23.11 1051 00 18.03 816 00 23.37 1062 00 18.29 832 00 23.62 1074 00 18.54 843 00 23.88 1085 00 18.79 854 00 24.13 1096 00 19.05 866 00 24.
23、38 1108 00 19.30 877 00 24.64 1119 00 19.56 889 00 24.89 1131 00 19.81 901 00 25.15 1143 00 20.06 913 00 25.40 1155 00 20.31 924 00 25.65 1166 00 20.57 935 00 25.91 1177 00 20.83 947 00 16.16 1189 00 21.08 958 00 26.42 1200 00 21.34 970 00 26.67 1212 00 21.59 981 00 26.93 1224 00 21.84 993 00 27.18 1235 00 22.10 1005 00 27.43 1247 00 22.35 1016 00 27.69 1258 00 22.61 1028 00 27.94 1270 00 22.86 1039 00
