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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: (412) 772-8512 FAX: (412) 776-0243 TO PLACE A DOCU
3、MENT ORDER; (412) 776-4970 FAX: (412) 776-0790 SAE WEB ADDRESS http:/www.sae.org Copyright 1989 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 J101 REV. DEC89 Issued1973-03 Revised1989-12 Superseding J101 MAR85 (R) HYDRAULIC WHEEL CYLINDERS FOR AUTOMOTIVE DRUM BRAKES ForewordThis Document has not changed other than to put it into the new SAE Technical Standards Board Format. 1.ScopeThis document specifies minimum performance and dura
5、bility requirements for satisfactory vehicle usage, and it is applicable to wheel cylinder assemblies from commercial production, after production shipment, shelf storage, and remanufacture (factory rebuild). 2.References 2.1Related PublicationsThe following publications are provided for information
6、 purposes only and are not a required part of this document. 2.1.1SAE PUBLICATIONSAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001. SAE J1603Rubber Seals for Hydraulic Disc Brake Cylinders SAE J1703 OCT88Motor Vehicle Brake Fluid 2.1.2ASTM PUBLICATIONAvailable from ASTM, 100 Bar
7、r Harbor Drive, West Conshohocken, PA 19428-2959. ASTM D 1149Test Method for Rubber DeteriorationSurface Ozone Cracking in a Chamber (Flat Specimens) 3.PurposeThis document applies to wheel cylinder assemblies used on hydraulically operated, drum-type brakes of highway vehicles. It covers such cylin
8、ders where they are employed in passenger car, truck, bus, and like brake systems utilizing motor vehicle brake fluids that conform to SAE J1703. 4.RequirementsA wheel cylinder assembly shall, when tested in accordance with the procedures of Section 7, meet the following requirements: 4.1Unrestricte
9、d Apply and ReleasePer 7.1.2, the piston(s) must move smoothly throughout full stroke after starting, and must be completely returned to original position on the fifth stroke within 30 s by the force of the piston return spring, or, in the absence of a return spring, by 5 psi (34 kPa) maximum air pr
10、essure at inlet port. 4.2Ozone ResistancePer 7.2, the boot(s) shall not be perforated or cracked through in any areas. (7.2 is a conditioning test of the wheel cylinder for other tests which follow, and the cylinder should be rejected if deterioration of the boot obviously precludes meeting subseque
11、nt test requirements.) SAE J101 Revised DEC89 -2- 4.3Applied Leakage 4.3.1Per 7.3.1, there shall be no drop in pressure in excess of 1 psi (7 kPa) in a 30 s interval. 4.3.2Per 7.3.2, there shall be no drop in pressure in excess of 50 psi (345 kPa) in a 30 s interval. 4.4Physical StrengthPer 7.4.1, t
12、he gage shall show no abrupt pressure drop and the cylinder shall show no signs of mechanical failure. 4.5Humidity Operation 4.5.1Per 7.5.1, the wheel cylinder piston(s) must fully apply the load fixture(s) to its bottom or stop and allow it to return to the full release stop within a stroke cycle o
13、f the master cylinder. 4.5.2Per 7.5.3, see requirements 4.3.1 and 4.3.2. 4.6High Temperature Durability 4.6.1Per 7.6.1, see requirement 4.5.1. 4.6.2Per 7.6.2, there shall be no visible leakage at the wheel cylinder bleed screw or hydraulic connector(s) and leakage at each boot of the wheel cylinder
14、shall not be measurable. 4.6.3Per 7.6.3, leakage at each boot shall not exceed five drops. 4.6.4Per 7.6.4, see requirements 4.3.1 and 4.3.2. 4.7Cold Temperature Operation 4.7.1Per 7.7.1, see requirement 4.5.1. 4.7.2Per 7.7.2, there shall be no visible leakage at the wheel cylinder bleed screw or hyd
15、raulic connector(s), and leakage at each boot of the wheel cylinder shall not exceed five drops. 4.7.3Per 7.7.3, see requirements 4.3.1 and 4.3.2. 4.8Storage Corrosion Resistance 4.8.1Per 7.8.1, there shall be no visible leakage at the wheel cylinder bleed screw or hydraulic connector(s), and leakag
16、e at each boot shall not exceed five drops. 4.8.2Per 7.8.2, piston(s) must start to move at 40 psi (276 kPa) maximum pressure. 4.8.3Per 7.8.3, the wheel cylinder piston(s) must fully apply the load fixture to its bottom or stop and return it to full release stop. 4.8.4Per 7.8.4, see requirements 4.3
17、.1 and 4.3.2. 4.9Static LeakagePer 7.9.1, there shall be no visible fluid leakage in the trap(s). 4.10 Examination 4.10.1 Per 7.10.1, wheel cylinders up to and including 2 in (50.8 mm) bore diameter shall have 0.080 in (2.03 mm) minimum diameter at the smallest opening of the hydraulic inlet(s). SAE
18、 J101 Revised DEC89 -3- 4.10.2 Because these specifications spell out only minimum requirements, none are called for per 7.10.3. 5.Test ApparatusThe basic apparatus shall be that shown and as arranged in Figure 1 or equivalent. All hydraulic lines and fittings shall be of sufficient size as to permi
19、t unrestricted fluid flow to and from the test wheel cylinder(s). The apparatus shall operate per the following description and as called for in Section 7. FIGURE 1TEST APPARATUS 5.1Master Cylinder AssemblyThe master cylinder should be one commercially representative of the brake system(s) in which
20、the test wheel cylinder(s) is (are) used. Its bore size and stroke will depend on the numbers and bore sizes of wheel cylinders to be stroke tested simultaneously. The referee master cylinder of SAE J1703 is one commercially representative.1 A shutoff valve shall be provided at the hydraulic outlet
21、of the master cylinder. 1.Referee master cylinders, of 1-1/8 in (28.6 mm) diameter bore and 1-7/16 in (36.5 mm) total stroke, may be obtained from Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15096. SAE J101 Revised DEC89 -4- 5.2Pressure Actuating MechanismThe pressu
22、re actuating mechanism shall apply an axial force to the master cylinder push rod without side thrust, and it shall allow the pressure in the master cylinder to return to 0 psi (0 kPa) when it is in the released position. Means must be provided for the actuating mechanism to stroke the master cylind
23、er both singly and cyclically. For single stroke operation, the means must be capable of generating pressures in the master cylinder up to 3000 psi (20.7 MPa) and it must have adjustment such that pressures of 20, 1000, and 3000 psi (0.14, 6.9, and 20.7 MPa) can be held statically after they are ach
24、ieved. For cyclic operation, the pressure actuating mechanism must be capable of generating pressures in the master cylinder up to 1000 psi (6.9 MPa) and have adjustments such that pressure can be peaked out at both 500 psi (3.4 MPa) and 1000 psi (6.9 MPa). Further, it must build up both of these pr
25、essures uniformly in 1.6 to 2.0 s, and be capable of doing so at any stroke of the master cylinder up to 90% of its total stroke. The pressure actuating mechanism, when releasing, must permit the full retraction of the master cylinder push rod. The means for cycling the pressure actuating mechanism
26、shall permit adjustment of uniform apply/release strokes at rates of both 500 and 1000 cycles/h. 5.3Load FixtureThe load fixture, such as that shown in Figure 2, must stroke 0.12 + 0.0 0.5 in (3.05 + 0.0 0.5 mm) in each load cell at a hydraulic pressure buildup in the wheel cylinder within the limit
27、s shown by the curves of Figure 3. It must accommodate both single- and double-ended wheel cylinders and mount them as they would be mounted on their brakes; it must accommodate both insert and socket-type wheel cylinder pistons; it must be capable of placing 4 deg 0.5 angularity on connecting link(
28、s) with respect to the wheel cylinder bore longitudinal axis; and it must accommodate wheel cylinders of 5/8 to 2 in (15.9 to 50.8 mm) diameter. (This is a composite description of load fixture requirements. At least two load fixtures with appropriate differences in design would be necessary for tes
29、ting all types and sizes of wheel cylinders.) FIGURE 2WHEEL CYLINDER LOAD FIXTURE SAE J101 Revised DEC89 -5- FIGURE 3LOAD FIXTURE PERFORMANCE CURVES Ends of connecting links engaging wheel cylinder pistons must be per those links actually used on brakes by the vehicle manufacturer from the standpoin
30、t of their piston and boot fits. Locks must be provided for the connecting links at their load cell ends. NOTEActual brake assemblies, such as shown in SAE J1703 or equivalent fixtures, such as shown in SAE J1603 may be used in place of the above fixture providing they meet its requirements and thos
31、e of Section 7. Single-end wheel cylinders, such as those for two leading, floating shoe brakes, and whose reactive loads are taken by brake shoes as well as cylinder mountings, should be tested in pairs as part of a complete brake and drum assembly. 5.4InstrumentationTwo hydraulic pressure measurin
32、g devices shall be employed, each equipped with a shutoff valve. One shall have a range of 0 to 30 psi (0 to 207 kPa) and the other shall have a range of 0 to 5000 psi (0 to 34.5 MPa). Both shall be of a type that requires negligible hydraulic displacement and is equipped with a bleeder. A mechanica
33、l or electrical counter shall be used to record the number of strokes during cyclic operation. A leak trap shall be provided for each wheel cylinder boot. It shall have minimum exposed area in order to minimize evaporation. SAE J101 Revised DEC89 -6- A 24 to 48 in (610 to 1220 mm) height standpipe s
34、hall be provided as shown in Figure 1. 5.5Environmental Equipment 5.5.1OZONE CHAMBERAn ozone chamber as described in ASTM D 1149-81, Standard Test Method for Rubber Deterioration - Surface Ozone Cracking in a Chamber (Flat Specimens). It must maintain 50 pphm by volume at 37.7 C 3 C (100 F 5 F) ozon
35、e concentration. 5.5.2HEATED AIR BATH CABINETAn insulated oven or cabinet having sufficient capacity to house the load fixtures of the test apparatus. A suitable thermostatically controlled heating system is required to maintain a temperature of 100 C 5 C (212 F 9 F). Heaters shall be shielded to pr
36、event direct radiation to the wheel cylinders. 5.5.3COLD CHAMBERA cold chamber shall be provided having sufficient capacity to house the load fixtures of the test apparatus. It shall be such that the apparatus can be checked and operated without removal, and it shall be capable of maintaining a unif
37、orm atmosphere of cold dry air at 40 +2, 5 C (40 +3.6, 9 F) temperature. 5.5.4HUMIDITY CABINETA humidity cabinet having sufficient capacity to house the load fixtures of the test apparatus. It shall be capable of maintaining a relative humidity of 95% 3 at temperatures of 21 C 3 C (70 F 5 F) and 46.
38、1 C 3 C (115 F 5 F). 5.6Test Fittings and MaterialTest hydraulic fluid shall be per SAE J1703. The compatibility fluid of SAE J1703 is recommended.2 Wheel cylinder bolts and their lock washers shall be of types used by the vehicle manufacturer. The hydraulic connector to the wheel cylinder, whether
39、tubing or hose, shall also be of the type used by the vehicle manufacturer. 6.Test SamplesWheel cylinders for test shall not have been used after manufacture or rebuild, and they shall not be disassembled prior to testing. 7.Test Setup And ProceduresTests shall be conducted in the sequence shown and
40、 at room temperature except where otherwise specified. Wheel cylinders shall not be disassembled until after all tests are completed or unless testing is discontinued. 7.1Unrestricted Apply and Release 7.1.1Remove the shipping plug from the wheel cylinder hydraulic inlet port(s). 7.1.2Fully stroke t
41、he cylinder five times by hand and allow it to return under the piston return spring load. In the absence of a piston return spring, apply 5 psi (34 kPa) air pressure to the inlet port until the cylinder returns to its original position, five times. Record time for return on fifth stroke. NOTEAvoid
42、stroking the wheel cylinder cups into the bleed screw and/or hydraulic inlet openings during this test. 7.2Ozone ResistanceSeal the hydraulic port(s) from the atmosphere, install connecting link(s) where required to seal the small diameter of the boot, and place the cylinder in the ozone chamber. Su
43、bject the cylinder to an ozone concentration of 50 pphm 5 by volume at 37.7 C 3 C (100 F 5 F) for 50 h. Remove the cylinder from the ozone chamber and visually inspect the boot(s) without disassembling. 2.Compatibility fluid may be obtained from Society of Automotive Engineers, Inc., 400 Commonwealt
44、h Drive, Warrendale, PA 15096. SAE J101 Revised DEC89 -7- 7.3Applied LeakageInstall the wheel cylinder on its load fixture and tighten the mounting bolts by hand. (See Note of 5.3 for single-end wheel cylinders.) Making certain that the piston(s) is (are) not beyond the brake release position and th
45、at the connecting link(s) has (have) 4 deg 0.5 deg angularity with the wheel cylinder bore longitudinal axis, tighten the mounting bolts to the nominal torque specified by the vehicle manufacturer. Adjust the connecting link(s) so that the piston(s) is (are) in the release position. Assemble the hyd
46、raulic connector of the test apparatus to the wheel cylinder and tighten to the nominal torque specified by the vehicle manufacturer. Fill the test setup with new hydraulic fluid and bleed at all points in the system as necessary to remove air. Tighten the bleed screw to the nominal torque specified
47、 by the vehicle manufacturer. 7.3.1Drop the connecting link lock(s) in place per Figure 2 and open the valve to the low pressure gage. Apply the master cylinder to build up 20 psi 1 psi (138 kPa 6.9 kPa) pressure in the system, shut off the valve to the master cylinder, and release the master cylind
48、er. Allow the pressure to the wheel cylinder to stabilize for 15 to 20 s, and then record the pressure at the beginning and end of a 30 s 1 s interval. 7.3.2Open the valve to the master cylinder, close the valve to the low pressure gage, and open the valve to the high-pressure gage. Apply the master
49、 cylinder to build up 1000 psi 100 psi (6.9 MPa 0.7 MPa) pressure in the system, shut off the valve to the master cylinder, and release the master cylinder. Allow the pressure to the wheel cylinder to stabilize for 15 to 20 s, and then record the pressure at the beginning and end of a 30 s 1 s interval. 7.4Physical StrengthOpen the valve to the master cylinder and apply the master cylinder to build up 3000 psi 300 psi (20.7 MPa 2 MPa) pressure in the system. Hold the pressure for 15 s