Review of Seatbelt Anchorage and Dimensions of Test Bench Seat Cushion JASIC
Motivation and Purpose There is no definition about whether seatbelt anchorage should be fixed or not. We tested the same test conditions except for that the ISOFIX anchorage is fixed or movable, and the injury measures of a dummy were compared. From those results, we reviewed that the seatbelt anchorage should be fixed or movable. 2
Side Impact Test Methods We used acceleration type sled test system We used Q3 dummy We tested 2 kinds of ISOFIX type CRS 3
CRS CRS-A CRS-B 4
Door Velocity, and Relative Velocity between Door and Seat Velocity [m/s] 速 度 [m/s] 10 9 8 7 6 5 4 3 CRS-A Velocity 速 度 [m/s] [m/s] 10 9 8 7 6 5 4 3 CRS-B 2 2 1 1 0 0 10 20 30 40 50 60 70 80 Time 時 間 [ms] 0 0 10 20 30 40 50 60 70 80 Time 時 間 [ms] Movable ISOFIX anchorage Corridor Fixed ISOFIX anchorage The door velocities were in Corridor The relative velocities when ISOFIX anchorage fixed were out of corridor after 50ms, but it was the time after the maximum dummy injury measures. So we think it was not influenced to the comparisons. 5
Test Video of CRS-A Movable ISOFIX anchorage Fixed ISOFIX anchorage 6
Dummy Accelerations (CRS-A) Acceleration 加 速 度 [m/s 2 [m/s ] 2 ] Acceleration 加 速 度 [m/s [m/s 2 ] 2 ] 1200 1000 800 600 400 200 0 1600 1400 1200 1000 800 600 400 200 0 Head Acceleration 100 0 0 10 20 30 40 50 60 70 80 Time 時 間 [ms] Pelvis Acceleration 0 10 20 30 40 50 60 70 80 時 間 [ms] Time [ms] Acceleration [m/s 2 ] 加 速 度 [m/s 2 ] 1000 900 800 700 600 500 400 300 200 Chest Acceleration 0 10 20 30 40 50 60 70 80 Time 時 間 [ms] Movable ISOFIX anchorage Fixed ISOFIX anchorage 7
Test Video of CRS-B Movable ISOFIX anchorage Fixed ISOFIX anchorage 8
Dummy Accelerations (CRS-B) Acceleration [m/s 2 ] Acceleration [m/s 2 ] 加 速 度 [m/s 2 ] 加 速 度 [m/s 2 ] 1200 1000 800 600 400 200 0 1600 1400 1200 1000 800 600 400 200 0 Head Acceleration 1000 900 800 700 600 500 400 300 200 100 0 0 10 20 30 40 50 60 70 80 Time 時 間 [ms] Pelvis Acceleration 0 10 20 30 40 50 60 70 80 Time 時 間 [ms] Acceleration [m/s 2 ] 加 速 度 [m/s 2 ] Chest Acceleration 0 10 20 30 40 50 60 70 80 Time 時 間 [ms] Movable ISOFIX anchorage Fixed ISOFIX anchorage 9
Maximum Dummy Injury Measures CRS-A CRS-B Region Injury measure Unit Threshold ISOFIX Anchorage ISOFIX Anchorage Movable Fixed Movable Fixed HPC15-800 523 533 697 713 Head 3ms Acceleration G 80 81.5 82.6 90.9 89.2 Chest deflection mm - 18.9 16.1 21.4 21.2 Chest 3ms Acceleration G - 47.1 47.9 60.8 57.5 Pelvis 3ms Acceleration G - 83.5 89.5 108.2 104.9 10
Photos of CRS Before / After Test (CRS-A) Movable ISOFIX anchorage Fixed ISOFIX anchorage Before After 11
Photos of CRS Before / After Test (CRS-B) Movable ISOFIX anchorage Fixed ISOFIX anchorage Before After 12
Photos of ISOFIX Connector after Tests Fixed ISOFIX anchorage CRS-A CRS-B 13
Photos of ISOFIX Connector after Tests Fixed ISOFIX anchorage (CRS-A) ISOFIX connector was broken. 14
Conclusion about ISOFIX Anchorage Injury measures under conditions that the ISOFIX anchorage was fixed and movable were almost similar. There were cases that ISOFIX connector lever could not be moved when ISOFIX anchorages were fixed, so we could not release the ISOFIX connector and it took a long time to remove a CRS from the test bench seat. It was easy to remove a CRS from the ISOFIX anchorage when the ISOFIX anchorages were movable. We think it is better that the ISOFIX anchorage is movable. 15
Side Impact Test Methods We used acceleration type sled test system We used Q3 dummy We tested CRS fixed by seatbelt 16
Conclusion about Seatbelt Anchorage It was easy to remove CRS fixed by seatbelt from test bench seat. A movable seatbelt anchorage may make structure of the jig complex. It is considered that a fixed seatbelt anchorage is an advantage because the different between fixed and movable anchorages has a small effect on injury measures. 17
Dimensions of Test Bench Seat Cushion There are cutouts in a seat defined in the new regulation. The difference between fixed and movable anchorages has a small effect on injury measures. Injury measures are almost the same regardless of a distance when a CRS moves on a seat. There is no influence of a friction. 18
Dimensions of Test Bench Seat Cushion A seat shape has a small effect. We think it is better that a seat shape is simple because it is easy to make the cushion, for example, like the shape defined in UN. 19
Dimensions of Test Bench Seat Cushion for Side Impact T=0ms is defined when a door surface reaches the position of 350mm from the center of a CRS. T=0ms is the time when a door reaches the position of 50mm from a seat end. 20
Setting of T=0ms for Side Impact Test Door reaches a seat end Door reaches the position of 50mm from a seat end It is easier to set T=0ms for the time when a door reaches a seat end than the time when a door reaches the position of 50mm from a seat end. We think it is better that the center of a CRS is the position of 350mm from a seat end for the seat cushion of side impact test. 21
Dimensions of Test Bench Seat Cushion for Side Impact 225 350 400 250 The center of a CRS is located between 350mm and 400mm from a seat end. (Only for side impact test) 22