1、 FORD LABORATORY TEST METHOD BJ 014-01 Date Action Revisions 2001 07 24 Revised Editorial no technical change A. Cockman 1992 05 12 Printed copies are uncontrolled Page 1 of 7 Copyright 2001, Ford Global Technologies, Inc. MODIFIED FOUR-BALL FRICTION TEST Application This procedure is used to determ
2、ine the frictional characteristics of automatic transmission fluids with clutch plate materials at various temperatures. Apparatus Required 1. Ford modified four-ball friction apparatus consisting of a four-ball wear tester with the following modifications similar to original changes suggested by Sh
3、ell Oil Company: (a) The spring type torque sensing device has been replaced with a strain gage. (b) The driving pulley arrangement at the spindle end has been modified to incorporate a magnetic clutch and flywheel, 9 1/2 inch in diameter and weighing approximately 35 lb. The flywheel has been secur
4、ed to the spindle with a pin so that it rotates with the spindle. The pulley has been made independent of the spindle with ball bearings and operates as a unit with the flywheel only when the magnetic clutch is energized. 2. A fixture to accommodate flat steel discs as the top specimen and a fixture
5、 to hold 1 1/4 inch discs of friction material as the bottom specimen. Either top or bottom fixture must be self-aligning. Drawings illustrating the Ford fixture are included. 3. Flat steel disc specimens and friction discs of specified material. Drawings of specimens are included. 4. Torque and spe
6、ed sensing devices and a suitable recorder or recorders. Example: Servo-tek generator and strain gage in conjunction with a Brush Amplifier and a Mosley Autograph X-Y recorder to directly plot coefficient of friction versus speed. 5. Temperature controller. 6. Solvents - benzene and N-pentane. 7. Va
7、rious grades of polishing paper. 8. A timer to allow uniform break-in periods from sample to sample. FORD LABORATORY TEST METHOD BJ 014-01 Page 2 of 7 Copyright 2001, Ford Global Technologies, Inc. Conditioning and Test Conditions All test values indicated herein are based on material conditioned in
8、 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. Preparation (a) The upper steel specimen is polished with decreasing grades of polishing cloth, the final poli
9、sh to be made with crocus cloth. (b) The sample holder, lower disc holder, and upper disc are cleaned thoroughly with benzene followed by N-pentane. (c) The lower friction material disc is inserted in the sample holder. (d) The fluid to be tested in introduced into the sample holder. (e) The apparat
10、us is assembled on the machine. 2. Warm-up (a) The setup is broken in for a period of 15 minutes at a temperature of 100 F at a speed of 600 rpm and at the load corresponding to the unit pressure specified in the test. (b) With the machine shut off, the X-Y recorder is zeroed and the spread is adjus
11、ted using a resistor having a resistance which will simulate a given torque or coefficient reading. The set-up is now ready for test. 3. Test Procedure (a) The machine is put on manual control and accelerated to 600 rpm, at which speed the motor is shut off and the clutch is disengaged and the coast
12、-down speed versus the coefficient of friction is plotted on the X-Y recorder at 100 F. (b) The temperature control is adjusted to give a temperature of 250 F and the same procedure is run at this temperature. Note: Other temperatures may be run if requested. FORD LABORATORY TEST METHOD BJ 014-01 Pa
13、ge 3 of 7 Copyright 2001, Ford Global Technologies, Inc. Limits of Variables 1. Temperature - room temperature to 300 F. 2. Unit load - maximum of 500 psi. 3. Sliding speed - 0 - 185 ft/min. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Eac
14、h party is responsible for determining proper use and handling in its facilities. FORD LABORATORY TEST METHOD BJ 014-01 Page 4 of 7 Copyright 2001, Ford Global Technologies, Inc. MODIFIED FOUR-BALL FRICTION TEST FORD LABORATORY TEST METHOD BJ 014-01 Page 5 of 7 Copyright 2001, Ford Global Technologi
15、es, Inc. MODIFIED FOUR-BALL FRICTION TEST FORD LABORATORY TEST METHOD BJ 014-01 Page 6 of 7 Copyright 2001, Ford Global Technologies, Inc. MODIFIED FOUR-BALL FRICTION TEST FORD LABORATORY TEST METHOD BJ 014-01 Page 7 of 7 Copyright 2001, Ford Global Technologies, Inc. MODIFIED FOUR-BALL FRICTION TEST
