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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: (724) 772-8512 FAX: (724) 776-0243 TO PLACE A DOCU
3、MENT ORDER; (724) 776-4970 FAX: (724) 776-0790 SAE WEB ADDRESS http:/www.sae.org Copyright 1991 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 J1570 REV. SEP91 Issued1988-10 Revised1991-09 Superseding J1570 OCT88 (R) RUBBER DUST BOOTS FOR THE HYDRAULIC DISK BRAKE PISTON 1.ScopeThis SAE Standard covers molded rubber boots used on disc brake pistons to prevent the entrance of dirt and moisture which could cause corrosion and otherwise
5、impair caliper operation. The specification includes performance tests of brake piston boots of both plain and insert types under specified conditions and does not include requirements relating to chemical composition or physical properties of the rubber compound. Further, it does not cover the stre
6、ngth of the adhesion of rubber to the insert material where an insert is used. The rubber material used in these boots is classified as suitable for operating in a temperature range of 40 to + 120 C 2 C (40 to + 248 F 3.6 F). 2.References 2.1Applicable PublicationsThe following publications form a p
7、art of this specification to the extent specified herein. The latest issue of SAE publications shall apply. 2.1.1SAE PUBLICATIONSAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001. SAE J1601Rubber Cups for Hydraulic Actuating Cylinders 2.1.2ASTM PUBLICATIONSAvailable from ASTM, 19
8、16 Race Street, Philadelphia, PA 19103. ASTM D 471Test Method for Rubber Property-Effect of Liquids ASTM D 573Test Method for Rubber-Deterioration in an Air Oven ASTM D 1149Test Method for Rubber Deterioration-Surface Ozone Cracking in a Chamber ASTM D 1415Test Method for Property-International Hard
9、ness ASTM D 2240Test Method for Rubber Property-Durometer Hardness 3.General Requirements 3.1Workmanship and FinishBoots shall be free from blisters, pinholes, cracks, protuberance, embedded foreign material, or other physical defects which can be detected by thorough inspection, and shall conform t
10、o the dimensions specified on the drawings. 3.2MarkingThe identification mark of the manufacturer as recorded by the Rubber Manufacturers Association and other details as specified on drawings shall be molded into each boot. SAE J1570 Revised SEP91 -2- 3.3PackagingBoots shall be packaged to meet req
11、uirements specified by the purchaser. 3.4SamplingThe minimum lot on which complete specification tests shall be conducted for quality control testing, or the frequency of any specific type test used to control production, shall be agreed upon by the manufacturer and the purchaser. 4.Test Requirement
12、s 4.1Resistance to Fluid at Elevated TemperatureAfter being subjected to the test for resistance to fluid at elevated temperatures as prescribed in 5.4, boots shall conform to the following requirements: a.Change in volume: 5 to +20% b.Change in hardness: 15 to +5 points c.IRHD (Shore A) 4.2Heat Str
13、oking TestAfter stroking as detailed in 5.5, boots will have passed the requirements if the following criteria are met: a.Both beads must remain in installed position during stroking. b.IRHD hardness change must not exceed 10 to +15 points. c.Boots must not be cracked through (surface cracking allow
14、ed) after completion of the stroking and removal from the caliper or fixture. d.Clearance must not occur at the interference points measured per 5.5.2. 4.3Low Temperature Stroking TestDuring stroking as detailed in 5.6, boots shall be considered to have passed the test if the following criteria are
15、met: a.Boot beads shall remain in the installed position during stroking. b.No cracks caused by flexing at low temperature shall be in evidence. 4.4Heat Resistance Test (Static)After the heat resistance test, as described in 5.7, boots shall conform to the following requirements: a.The boots must no
16、t be cracked through (surface cracking allowed) after installation, flexing, and removal. b.Change in IRHD (Shore A) hardness: 5 to +20 points 4.5Ozone Resistance TestAt the end of the 168 h exposure period, as detailed in 5.8, test specimens shall be removed from the ozone chamber and examined unde
17、r 2X magnification while in the installed position. Surface of the test specimens shall show no evidence of cracking, rupture, or other deterioration. 5.Test Procedures 5.1Test SpecimensSpecimens prepared for a particular test shall be cut from the same approximate location on different sample boots
18、. Hardness test specimens shall be prepared to present a flat molded surface to the indentor. 5.2Test FluidThe brake fluid used for testing shall be that specified in Appendix A. 5.3HardnessThe method of determining rubber hardness shall be as described in ASTM D 1415. If agreed upon by vendor and p
19、urchaser, an alternate procedure, ASTM D 2240 may be used. SAE J1570 Revised SEP91 -3- 5.4Resistance to Fluids at Elevated Temperatures 5.4.1APPARATUS a.OvenCirculating air oven as specified in Section 5 of ASTM D 573. b.ContainerUse a screw top, straight-sided, round glass jar, having a capacity of
20、 approximately 250 cm3 and inner dimensions of approximately 125 mm in height and 50 mm in diameter, and tinned steel lid (no insert or organic coating). 5.4.2TEST SPECIMENSTwo new test segments weighing 0.5 to 5 g shall be cut from complete boots. 5.4.3TEST PROCEDURE a.The segments shall be rinsed
21、in isopropyl alcohol, and blown dry or wiped dry with a lint-free cloth to remove dirt and packaging debris. The segments shall not remain in the alcohol for more than 30 s. b.Determine and record the volume of the segments in accordance with Section 10 of ASTM D 471, except use isopropyl alcohol wh
22、ere acetone is specified. c.Determine and record the initial IRHD hardness of test segments. d.The segments shall be placed in a suitable glass container and completely immersed in 75 mL of the approved brake fluid, and the container shall be sealed to prevent vapor loss and placed in an oven at 120
23、 C 2 C (248 F 3.6 F) for 70 h followed by removal per ASTM D 471. e.Determine and record the final volume and IRHD (Shore A) hardness of the segments. 5.4.4CALCULATIONS a.Volume ChangeThe change in volume shall be reported as percentage of the original volume. The calculations shall be made as follo
24、ws: (Eq. 1) where: M1 = initial mass in air M2 = initial mass in water M3 = mass in air after test M4 = mass in water after test b.Hardness ChangeCalculate and record the change in IRHD (Shore A) hardness. 5.5Heat Stroking Test 5.5.1APPARATUS a.OvenCirculating air oven as specified in Section 5 of A
25、STM D 573. b.Actuated Stroking FixtureThis fixture shall be composed of a production caliper assembly or simulating fixture capable of being stroked 0.020 in at the one-half worn lining piston position. c.Actuating Stroking FixtureThis fixture shall be composed of a mechanically, pneumatically or hy
26、draulically actuated device whose rate of operation shall be controlled at 1000 strokes per hour 100 strokes per hour. d.DrawingA drawing of a typical actuated and actuating system is shown in SAE J1601, Figure 1. % Increase in Volume M3M4()M1M2() M1M2() - -100= SAE J1570 Revised SEP91 -4- 5.5.2TEST
27、 SPECIMEN PREPARATION a.Two new boots shall be rinsed in isopropyl alcohol and blown dry or wiped dry with a lint-free cloth to remove dirt and packaging debris. b.The boots shall not remain in the alcohol for more than 30 s. Measure and record IRHD (Shore A) hardness of boots. c.Measure, record, an
28、d calculate boot-to-piston and boot-to-caliper groove interferences (diametral and/ or side interference at sealing bead, as designed). d.Install the dry boots on the caliper assembly or fixture. 5.5.3TEST PROCEDURE a.Place the caliper assemblies or fixtures (adjusted to simulate the one-half worn l
29、ining piston position) in the oven and connect as required. b.Stroke for 70 h at 1000 strokes per hour 100 strokes per hour at 120 C 2 C (248 F 3.6 F). If simulating fixtures are used, a stroke of 0.020 in shall be maintained. c.After 70 h, discontinue stroking, shut off heat and allow oven to cool
30、for 1 h with door open. Remove boots for inspection within 30 h. d.Note and record general condition of boots relative to cracks, retention of shape, and tackiness. e.Remeasure and record interference per 5.5.2. f.Remeasure and record IRHD (Shore A) hardness of boots. 5.6Low Temperature Stroking Tes
31、t 5.6.1APPARATUS a.Cold ChamberA cold chamber large enough to permit installation of the test caliper (or fixture) and capable of continuous 40 C (40 F) operation. b.CaliperA test caliper (or fixture) per SAE J1601 Figure 1, except modified to allow for stroking from upworn lining piston position to
32、 full worn lining piston position. c.ActuatorAn actuator capable of actuating the boot test caliper or fixture. 5.6.2TEST SPECIMEN PREPARATION a.Two new boots shall be rinsed in isopropyl alcohol and blown dry or wiped dry with a lint-free cloth. The test boot shall not remain in alcohol for more th
33、an 30 s. b.Install boots on calipers or fixtures and place in cold chamber. 5.6.3TEST PROCEDURE a.The test caliper or fixture shall be subjected to a temperature of 40 C 2 C (40 F 3.6 F). After a total of 70 h, stroke the calipers (or fixtures) from full lining piston position to full worn lining pi
34、ston position for six strokes, 10 s apart, without removal from the cold chamber. b.After return to ambient temperature, inspect for boot retention and remove boots from fixtures and note and record general condition of boots relative to cracks. 5.7Heat Resistance Test (Static) 5.7.1APPARATUSCircula
35、ting air oven as specified in Section 5 of ASTM D 573. SAE J1570 Revised SEP91 -5- 5.7.2TEST SPECIMEN PREPARATION a.Two new boots shall be rinsed in isopropyl alcohol and blown dry or wiped dry with a lint-free cloth to remove dirt and packing debris. The boots shall not remain in the alcohol for mo
36、re than 30 s. b.Measure and record IRHD (Shore A) hardness of the boots per 5.3. 5.7.3TEST PROCEDURE a.The test boots shall be placed in the circulating air oven and held for 22 h at 175 C 2 C (347 F 3.6 F). b.At the termination of the heating period, the boots shall be removed from the oven and all
37、owed to cool for 30 min at room temperature. c.The boots shall be visually inspected and the IRHD hardness, after aging, determined and recorded. Also, record any visual change in the boot. d.Install boots in normal manner, flex 10 times from new to full worn lining position and remove. 5.8Ozone Res
38、istance Test 5.8.1APPARATUSThe apparatus shall consist of an ozone chamber as described in ASTM D 1149, and shall be capable of maintaining an ozone partial pressure of 100 MPa 10 MPa (100 10 parts of ozone/100 million parts of air by volume). 5.8.2TEST SPECIMEN PREPARATIONTwo new test boots shall b
39、e installed on a caliper assembly or fixture which shall simulate the normal actual installation stretch at the piston and caliper assembly groove beads and the full worn lining piston position. 5.8.3TEST PROCEDURE a.Assemble two new test boots on the calipers or fixtures. b.Immediately after assemb
40、ly, the calipers or fixtures shall be placed in the chamber and exposed to an ozone partial pressure of 100 MPa 10 MPa (100 10 parts of ozone/100 million parts of air by volume) at a temperature of 40 C 1 C (104 F 1.8 F) for 7 days. c.After the 7-day period, remove the caliper or fixture and examine
41、 the boots for cracks under a 2X magnification while in the installed position. 6.Notes 6.1Marginal IndiciaThe change bar (l) located in the left margin is for the convenience of the user in locating areas where technical revisions have been made to the previous issue of the report. An (R) symbol to
42、 the left of the document title indicates a complete revision of the report. PREPARED BY THE SAE HYDRAULIC BRAKE ACTUATING ELASTOMERIC COMMITTEE SAE J1570 Revised SEP91 -6- APPENDIX A SAE RM-66-03 COMPATIBILITY FLUID1 A.1This fluid is a blend of four proprietary polyglycol brake fluids of fixed comp
43、osition, in equal parts by volume. The four fluids selected comprise three factory-fill and one aftermarket fluid, as follows: DOW HD50-4 DOW 455 Delco Supreme II Olin HDS-79 1.Obtainable from the Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15096-0001. SAE J1570 Rev
44、ised SEP91 RationaleAs noted in the Elastomeric Committee meeting of October 3, 1990, there is a strong feeling the referenced SAE J1570 recommended practice be made a full-fledged standard. Because of the maturity of rubber dust boots in disc brakes, the initial document approved in October, 1988 h
45、ad years of experience and practice backing it up. Since the formal issuance in October, 1988, the support has been widespread without any concerns or changes required by the automotive industry. It is therefore the recommendation of the Hydraulic Brake Actuating Elastomeric Committee that this docu
46、ment immediately be elevated to an SAE Standard. Appendix A has been changed in SAE J1570. The document has been reformatted due to the Technical Standards Board format. Section 2 References have been added to comply with the SAE Technical Standards Board format. All other section numbers have chang
47、ed due to the addition of Section 2. Relationship of SAE Standard to ISO StandardNot applicable. ApplicationThis SAE Standard covers molded rubber boots used on disc brake pistons to prevent the entrance of dirt and moisture which could cause corrosion and otherwise impair caliper operation. The spe
48、cification includes performance tests of brake piston boots of both plain and insert types under specified conditions and does not include requirements relating to chemical composition or physical properties of the rubber compound. Further, it does not cover the strength of the adhesion of rubber to
49、 the insert material where an insert is used. The rubber material used in these boots is classified as suitable for operating in a temperature range of 40 to +120 C 2 C (40 to +248 F 3.6 F) Reference Section SAE J1601Rubber Cups for Hydraulic Actuating Cylinders ASTM D 471Test Method for Rubber Property-Effect of Liquids ASTM D 573Test Method for Rubber-Deterioration in an Air Over ASTM D 1149Test Method for R