Sealing Robustness Improvements for Automotive Brake Tube Joint Systems SAE J2879 13 April 2011 Marty Kapanowski Chair, SAE Brake Component and Tube Joint Task Force
Overview Automotive Hydraulic Brake Systems Contain ~15-20 High Pressure Brake Tube Joints Building 1000 Units/Day Gives ~20,000 Opportunities For Leaks/Day Assembly Plants Have Difficulty Managing >~20 Brake Jobs Per Day Equating to Leaks On 0.1% of the Joints Secured That Day Leak Outbreaks Consume Hundreds of Thousands of Dollars Per Year in Engineers Time, Part Cost, Lab Analysis and Shipping, Often With No Tangible Result Question: Can inverted flare standards be updated to improve sealing performance of automotive brake tube joints? 13 April 2011 Kapanowski - SAE J2879 2
Current Inverted Flare Standards SAE J533 JASO F402-2001 2001 ISO 13486-1 SAE Traditional, familiar; slightly confusing, English tube sizes only, limited nut options, does not account for nylon-coated tubes JASO Metric tube sizes only, optional nut with long lead-in, does not account for nylon-coated tubes ISO 13486-1 Metric tube sizes only, virtual copy of JASO F402 with addition of direction to user to ensure nuts are compatible if plastic-coated tubes are used 13 April 2011 Kapanowski - SAE J2879 3
J533 Flare 13 April 2011 Kapanowski - SAE J2879 4
J512 Nut 13 April 2011 Kapanowski - SAE J2879 5
J512 Port Pick one 13 April 2011 Kapanowski - SAE J2879 6
JASO F402 Flare 13 April 2011 Kapanowski - SAE J2879 7
JASO F402 Nut 13 April 2011 Kapanowski - SAE J2879 8
JASO F402 Port 13 April 2011 Kapanowski - SAE J2879 9
ISO 13486-1 1 Flare 13 April 2011 Kapanowski - SAE J2879 10
ISO 13486-1 1 Nut 13 April 2011 Kapanowski - SAE J2879 11
ISO 13486-1 1 Port 13 April 2011 Kapanowski - SAE J2879 12
Resetting the Standard What steps can SAE members from OEMs and suppliers take to simplify and standardize brake tube joints? Benefits: Common tooling and designs at suppliers, if all OEMs adopt one standard Simplification of joint launch and troubleshooting post-launch at OEMs if all joints are same design 13 April 2011 Kapanowski - SAE J2879 13
First, Assemble a Team
First, Assemble a Team
Brake Component and Tube Joint Task Force Louis Damanti Jerome Schultz Paul Kuehl Dr Ing Han Zhao Leah Duby Mike VanHorn Janet Callahan Marty Kapanowski Karl Kleinhardt Randy Green Dave Homan Paul Carey Steve Kacines Myles Davis Sean Peterson Paul Gritt Micheline Brussow Jana Wright Larry Bishop Bruce Amble Jessica Marie Federico Chris Roberts Bosch Bosch Chrysler Continental Continental Cooper Standard Ford Ford GM Harco Harco Hi-Vol Hitachi Independent Martinrea Paul Gritt Consulting SAE SAE TI Automotive Toyota Toyota TRW 13 April 2011 Kapanowski - SAE J2879 16
Next, Fully Understand Current Standards, Generate Agreement on How the Joint Should Seal, and Why It Sometimes Does Not
How Does An Inverted Flare Joint Seal? Sounds Simple: Take Four Metal Cones Stack Them Up Squash Them Together With ~1800 lbf Expect Continuous 360-degree Contact Between the Bottom Two Cones, With Gap < ~10 microns 13 April 2011 Kapanowski - SAE J2879 18
Four Conic Sections (Frustums) This Should Seal Nicely F Nose of Nut Back of Flare Flare Sealing Surface Port Cone Seat 13 April 2011 Kapanowski - SAE J2879 19
Four Frustums Not So Much F Nose of Nut Back of Flare Flare Sealing Surface Port Cone Seat 13 April 2011 Kapanowski - SAE J2879 20
Geometry Observations Alignment Flare to seat Nut to flare Lateral stackup 13 April 2011 Kapanowski - SAE J2879 21
Interactions Between the Four Frustums Tube Does Not Drive Self-Centering In Spec! Contact Cone Deformation 13 April 2011 Kapanowski - SAE J2879 22
Flare / Seat Interactions Cone deforms, not flare, contrary to popular belief 13 April 2011 Kapanowski - SAE J2879 23
Nut / Flare / Port Interactions JASO F402 / SAE J533 Not to scale Proportions exaggerated to show differences 3/16 / 4.75mm ¼ / 6.0mm 5/16 / 8.0mm End view of this corner of tube flare can look like this. It is free-form mat l. Checked by pin gage for min diameter only. Poor initial contact surface. 13 April 2011 Kapanowski - SAE J2879 24
Nut / Flare / Port Interactions Q: Why Do Current Specifications Change Nut/Flare/Port Contact Relationship As Tube Diameter Increases? 13 April 2011 Kapanowski - SAE J2879 25
Nut / Flare / Port Interactions Q: Why Do Current Specifications Change Nut/Flare/Port Contact Relationship As Tube Diameter Increases? A: After Considerable Investigation, We Don t t Know! 13 April 2011 Kapanowski - SAE J2879 26
Interim Conclusions 3/16" joints seal better than 1/4" and 5/16" There are measurable differences between robust and non- robust joints Areas for improvement are: Flare thickness variation (TV) Concentricity Consistency of nut/flare/port interaction across tube sizes Put all the joint components into a single standard 13 April 2011 Kapanowski - SAE J2879 27
Meeting Schedule Initially bi-weekly then weekly face-to to-face at SAE After relationship-building and initial discussions moved to Webex/Conference Call Periodic face-to to-face meetings as needed 13 April 2011 Kapanowski - SAE J2879 28
Process Recognize and reconcile all theories of operation Assemble all existing specs into one matrix, pick optimum dimensions for each characteristic Perform stack-ups and mfg feasibility analyses Generate global agreement (OEM and Supplier) Build and test parts Review and concur on results Send spec for ballot (1 Oct 2010, Nov 2010 re-ballot with edits, April 2011 re-ballot with edits) 13 April 2011 Kapanowski - SAE J2879 29
Result 13 April 2011 Kapanowski - SAE J2879 30
SAE J2879 13 April 2011 Kapanowski - SAE J2879 31
SAE J2879 13 April 2011 Kapanowski - SAE J2879 32
SAE J2879 13 April 2011 Kapanowski - SAE J2879 33
SAE J2879 13 April 2011 Kapanowski - SAE J2879 34
J2879 Samples 13 April 2011 Kapanowski - SAE J2879 35
Nut / Flare / Port Interactions JASO F402 / SAE J533 Not to scale Proportions exaggerated to show differences 3/16 / 4.75mm ¼ / 6.0mm 5/16 / 8.0mm End view of this corner of tube flare can look like this. It is free-form mat l. Checked by pin gage for min diameter only. Poor initial contact surface. SAE J2879 3/16 / 4.75mm ¼ / 6.0mm 5/16 / 8.0mm 13 April 2011 Kapanowski - SAE J2879 36
Status Sent spec for ballot 1 Oct 2010 Approved with minor edits Nov 2010 re-ballot with edits April 2011 re-ballot with final edits 13 April 2011 Kapanowski - SAE J2879 37
Thank You Q & A