Delphi DM-890

Test Inst. No. DM-890 Rev. 07-Aug.-00 Page 1 of 5 INERTIA BRAKE DYNAMOMETER HOT ROUGHNESS SCREENING TEST Reliability Engineering & Test Development Reliability Engineer Approval/Date Laboratory Supervisor Approval/Date Staff Head Approval/Engineering/Date Distribution Original: File Copy 1 Copy 2 I. PURPOSE To determine high temperature in-stop torque fluctuations in disc brakes. This test was developed for the 1997 C/G/E/K-car. If another platform is to be tested, speeds and cycle times may need to be recalculated and then baselines re-established. II. SCOPE This standard specifies the severe, high temperature performance for all disc brake hardware. III. DATA SHEETS A. Comments sheet B. Disc Brake Measurements IV. EQUIPMENT REQUIRED Note: All test equipment is to be calibrated as required by Delphi Chassis procedures. A. Inertia brake dynamometer B. Thickness measuring equipment for shoe and linings, and rotors. C. Surface finish measuring equipment for rotor surface finish- in microinches(AA). D. Scales for weighing shoe and lining. E. The appropriate dynamometer fixture. V. TEST METHOD A. DEFINITIONS: None required. Test Inst. No. DM-890 Rev. 07-Aug.-00 Page 2 of 5 INERTIA BRAKE DYNAMOMETER HOT ROUGHNESS SCREENING TEST Reliability Engineering & Test Development B. PREPARATION 1. The Engineering Work Request submitted by the originator must reflect the following: (See S:\Wisengn\Dynamometer Lab\ dynarequest.xls) a) Vehicle manufacturer b) Vehicle model c) Model year d) Rolling radius e) Is setup for Gross Vehicle Weight or Lightly Loaded Vehicle Weight? Note: To simulate the mountain descents, the inertia shall be increased 15% above gross vehicle weight. f) One of the following: 1) Test Inertia 2) Total weight, and brake balance 3) Front weight, rear weight, C.G. height, and wheel base. 2. The preceding vehicle conditions will be assigned a Setup Number and stored on S:\Wisengn\Dynamometer Lab\Dyno\Data. If a previously established setup is requested, the Engineering Work Request need only reflect the Setup Number. 3. All setup information required and a complete description of the brake assembly tested will be documented in the EWR Report. 4. Thermocouple locations: a) Shoe and lining 1) Disc Brake aa) Install plug-type thermocouples 0.080” ( 2mm) below the rubbing surface, centrally radially and circumferentially in the inboard and outboard linings. bb) When it is not possible or practical to locate the thermocouples in radial or circumferential centerline, locate them in the O.D. area and/or leading as near to the requested position as practical. Document the thermocouple location used. Test Inst. No. DM-890 Rev. 07-Aug.-00 Page 3 of 5 INERTIA BRAKE DYNAMOMETER HOT ROUGHNESS SCREENING TEST Reliability Engineering & Test Development b) Rotor Install a plug-type thermocouple 0.040” ( 1mm) below the inboard and outboard rubbing surfaces centered radially between the vanes. 5. Initial measurements: a) Rotor surface finish (inboard and outboard). b) Rotor weight c) Rotor thickness (radial centerline of rubbing surface in four locations 90° apart) d) Shoe and lining thickness e) Shoe and lining weight (with thermocouples installed) f) Rotor runout: Lateral runout not to exceed 0.004 inch T.I.R. g) Record any unusual appearance of rotor, shoe, and lining. 6. Initial fluid displacement checks: a) Record blocked check brake fluid displacement at 1000 psi . b) Statically apply 1000 psi. to the brake assembly. Repeat until a stabilized value is obtained and record. C. TEST 1. Record calculated speed, torque, pressure, temperature and specific torque for all snubs. Record instantaneous torque data for the first and every fifth snubs (1, 5, 10, …40) for each heat cycle at 200 samples per second. Test Items Initial Speed (mph) Interval (sec.) Initial IB Rotor Temp. (°F) Deceleration (ft/sec2) Cooling Speed (mph) No. of Applies 1) Burnish 65 to 50 30 100 max. 8 65 50 2) Effectiveness Check 35 to 10 - 150 6 35 1 3) First Heat Cycle 75 to 60 15 150 450 psi. 75 40 4) 2nd Effectiveness Check 35 to 10 - 150 6 35 1 5) Second Heat Cycle 75 to 60 15 150 450 psi. 75 40 6) 3rd Effectiveness Check 35 to 10 - 150 6 35 1 7) Third Heat Cycle 75 to 60 15 150 450 psi. 75 40 Test Inst. No. DM-890 Rev. 07-Aug.-00 Page 4 of 5 INERTIA BRAKE DYNAMOMETER HOT ROUGHNESS SCREENING TEST Reliability Engineering & Test Development Notes: a) Attain torque level in .5 seconds. b) Cooling air velocity to be 30 mph @ 80°F for all brake applications. c) For each Burnish and Heat Cycle, first brake apply to be based on temperature, and the rest based on time interval. d) If in-stop torque variation of 100 ft-lb. or more is not achieved in at least one of the first 3 heat cycles, continue with the second set of heat cycles. 2. Second Set of Heat Cycles (Optional – See Note d) Test Items Initial Speed (mph) Interval (sec.) Initial IB Rotor Temp. (°F) Deceleration (ft/sec2) Cooling Speed (mph) No. of Applies 1) Second Burnish (Steps 9-15 Optional) 65 to 50 30 100 max. 8 65 25 2) Effectiveness Check 35 to 10 - 150 6 35 1 3) First Heat Cycle 75 to 55 15 150 450 psi. 75 30 4) 2nd Effectiveness Check 35 to 10 - 150 6 35 1 5) Second Heat Cycle 75 to 55 15 150 450 psi. 75 30 6) 3rd Effectiveness Check 35 to 10 - 150 6 35 1 7) Third Heat Cycle 75 to 55 15 150 450 psi. 75 30 Notes a) Attain torque level in .5 seconds. b) Cooling air velocity to be 30 mph @ 80°F for all brake applications. c) For each Burnish and Heat Cycle, first brake apply to be based on temperature, and the rest based on time interval. 3. Final measurements a) Rotor surface finish (inboard and outboard). b) Rotor weight c) Rotor thickness (radial centerline of rubbing surface in four locations 90° apart) d) Shoe and lining thickness e) Shoe and lining weight (with thermocouples installed) f) Record any unusual appearance of rotor, shoe, and lining Test Inst. No. DM-890 Rev. 07-Aug.-00 Page 5 of 5 INERTIA BRAKE DYNAMOMETER HOT ROUGHNESS SCREENING TEST Reliability Engineering & Test Development VI. TEST RESULTS A. The standard output for this test will be: 1. Lining measurements 2. Rotor measurements 3. Comments 4. A list of calculated data 5. A graph of torque variation vs. stop number B. Validation of test results Completed test results must reflect the equipment identification number (ID), the last calibration date, and the next calibration date. C. Distribution of test results All original data is to be attached to the original Engineering Work Request form and filed in the Engineering central file.