GMW14604Feb2007

WORLDWIDE ENGINEERING STANDARDS Test Procedure Interior GMW14604 Head Restraint Operational, Performance and Durability Tests © Copyright 2007 General Motors Corporation All Rights Reserved February 2007 Originating Department: North American Engineering Standards Page 1 of 8 1 Scope Note: Nothing in the standard supersedes applicable laws and regulations unless specific exemption has been obtained. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. The scope of this test procedure covers all kind of head restraints and their general requirements as well as tests. 1.1.1 Initial Sample Approval. The initial sample approval covers the determination of the height adjustment effort, the tilt adjustment moment and headrest integrity at impact in the rod direction. 1.1.2 Routine Quality Control. The routine quality control covers the determination of the height adjustment effort and the tilt adjustment moment. 1.1.3 Determination of the removal forces of front seat back head restraints and rear back head restraints. 1.1.4 Determination of the adjustment force of the rear back middle head restraint. 1.1.5 Determination of the durability of foldable head restraints (elasticity in horizontal direction). 1.1.6 Testing of additional requirements for: • Turn released head restraints • Push button released head restraints • Power head restraints 1.1.7 Testing of snap rods for head restraints by bend testing. 1.1.8 Testing of the integrity of the head rest system to guarantee the attachment of the headrest to the seat system in the rod direction. 1.1.9 Additional requirements. 1.2 Foreword. This test procedure focuses on the testing of head restraint system regarding durability, operational and performance requirements. 1.3 Applicability. All kind of GM head restraints in passenger cars, light duty and medium duty trucks. This includes head restraint systems with fixed height adjustment, foldable headrest at rear back, power headrest systems, and turn released headrests. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ECE R17 ISO 9001 FMVSS 201 SAE J826 2.2 GM Standards/Specifications. None 2.3 Additional References. ITDC Lab.-Drawing No. 412.074. 3 Resources 3.1 Facilities. An approved GM certified test lab with an adequate bed plate or equivalent work surface necessary for mounting the test sample and associated test fixtures appropriate for the procedure to be run. 3.2 Equipment. All measuring devices which will be used for measuring of travel/force and moment shall be calibrated according to ISO 9001. 3.2.1 All-purpose device (as far as possible) for all types of head restraints, which guarantees a high repeatability. The setup of the all-purpose device shall be according to ITDC Lab.-Drawing No. 412.074. 3.2.2 A suitable setup which shall be able to apply the required forces and moments. 3.2.3 Suitable measuring setups to measure force and travel as well as torque and angle of rotation. 3.2.4 An XY recorder to record the travel-force diagrams and torque-angle of rotation diagrams, or a recorder in accordance with the current state of the art. 3.2.5 Climatic chamber. 3.2.6 Spring balance with a follow-up pointer for measuring traction and pressure (maximum force), or equivalent measuring device. Measuring range: 250 N maximum. GMW14604 GM WORLDWIDE ENGINEERING STANDARDS © Copyright 2007 General Motors Corporation All Rights Reserved Page 2 of 8 February 2007 3.2.7 Suitable setup to release the foldable head restraint and move it back after folding. 3.2.8 Mounting Fixture. A means to support the seat system, including mounting blocks, or equivalent, simulating the floor attachment points to mount the seat in body position on a bed plate. 3.2.9 Weight. A 6.8 kg weight, generally a sandbag. 3.2.10 A fixture to clamp the snap rods. 3.2.11 For power systems, a device to operate the headset power switch. 3.2.12 Integrity Test. Head Impactor. Impactor with a semispherical head form and a 165 ± 2 mm diameter and a surface roughness of less than 1.6 µm, root mean square. The head form and associated base have a combined mass of 6.8 ± 0.05 kg. 3.2.13 Integrity Test - Propelling System. A propelling system to launch the head with 24.1 km/h and restrain the trajectory. 3.2.14 Manikin for the determination of H-Point and positions relative to H-Point according to the three dimensional SAE J826 (rev. Jul 95). 3.2.15 Heater lamp to simulate equivalent surface temperature (for durability test). 3.3 Test Vehicle/Test Piece. The test facilities and equipment shall be in good working order and shall have a valid calibration label. 3.3.1 Calibration. The test facilities and equipment shall be in good working order and shall have a valid calibration label. 3.3.2 Alternatives. Alternative test facilities and equipment may also be used. However, all measuring variables as specified in this specification shall be determined correctly with respect to its physical definition. 3.4 Test Time. For each test, considered individually: Calendar time: 14 days Test hours: 300 hours Coordination hours: 18 hours 3.5 Test Required Information. Samples of components or material released to this specification shall be tested for conformity with the requirements of this specification and approved by the responsible GM Department prior to the start of delivery of production level components or materials. Any change to the component or material e.g., design, function, properties, manufacturing process and/or location of manufacture requires a new release of the product. It is the sole responsibility of the supplier to provide the customer, unsolicited, with documentation of any change or modification to the product/process, and to apply for a new release. If not otherwise agreed to, the entire verification test shall be repeated and documented by the supplier prior to start of delivery of the modified or changed product. In some cases a shorter test can be agreed to between the responsible GM Department and the supplier. Obtain the Seat H-Point from the Design Release Engineer and GM Validation Engineer. 3.6 Personnel/Skills. Not applicable. 4 Procedure Specific preparation procedures are described at the respective test. 4.1 Preparation. 4.1.1 Test Samples. 4.1.1.1 First Sample Approval. A total of 15 samples are required for the test. For distribution and type of test, refer to Figure 1. 4.1.1.2 Routine Quality Control. A total of five samples are required for the routine quality control. Before and after the durability test, the adjustment forces and, if possible, the adjustment moments should be determined at +23 ± 5ºC. 4.2 Conditions. 4.2.1 Environmental Conditions. The conditioning depends on the test. For that reason, the conditioning will be given at the respective test. The durability test may be performed at temperatures representative of vehicle profile: (Validation Engineer to use engineering judgment based on materials used). 4.2.2 Test Conditions. Deviations from the requirements of the procedure shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. GM WORLDWIDE ENGINEERING STANDARDS GMW14604 © Copyright 2007 General Motors Corporation All Rights Reserved February 2007 Page 3 of 8 Figure 1: Plan of Test Samples 4.3 Instructions. 4.3.1 Test of Adjustment Force and Adjustment Moment. 4.3.1.1 General. 4.3.1.1.1 The test shall be performed at +23 ± 5ºC, at -20 ± 3ºC and at +60 ± 3°C. 4.3.1.1.2 The test shall be finished after ten minutes from removing the test piece from the climatic chamber. 4.3.1.1.3 Before measurements are taken, perform an up/down and forward/backward actuation. 4.3.1.1.4 After the measurement of the adjustment force and moment, the values shall be in compliance with the drawings. Before, during and after test, the headrest adjustment operation shall not produce any noise. 4.3.1.2 Measurement of Height Adjustment- Force. The test shall be performed to a complete padded head restraint or an unpadded head restraint (holder system). The complete head restraint is mounted in a seat subsystem. The seat has to be adjusted in design position (if unknown, 25 degrees). The notched sections of posts shall be in the tension direction of the machine. Distortion of the snap rods by mounting has to be avoided. GMW14604 GM WORLDWIDE ENGINEERING STANDARDS © Copyright 2007 General Motors Corporation All Rights Reserved Page 4 of 8 February 2007 The padded part of the head restraint and the holder system respectively shall be mounted in that way, that canting of the snap rods is avoided. The padded head restraint shall be mounted in that way, that the seat fits closely to the holder system. The head restraint frame shall be adjusted to its middle position (center of adjustment range). When tilting available, it shall be adjusted to rearmost position. Rotational force application points for the sliding force are provided on the left and right side of the outer flanks of the form. The so determined axis of rotation of the form should differ from the axis of rotation of the head restraint by 5 mm maximum. The adjusting force is applied to the lateral studs with little friction parallel to the notched section of the snap rods. Avoid canting due to non-uniform pulling or pressing of the snap rods. The padded head restraint and holder system respectively shall be moved from its bottom position through the entire adjusting range to the topmost notch and then back to the bottom position. Loading rate is 250 ± 10 mm/minimum. The actuation force versus displacement shall be determined: F = f(s). The result diagram shall be recorded with an XY recorder or a recorder in accordance with the current state of the art. Post lubrication shall not be affected by handling (touch dry lubricated). Engaging force/adjustment force shall be determined as the minimum value over total adjustment range. Figure 2: Vertical Adjustment 4.3.1.3 Measurement of the Tilt Adjustment Movement. The tilt adjustment moment is determined with a sheet metal frame embracing the frame head restraint upper and lower parts. This sheet metal frame is provided with drive journals at the outer flanks approximately in the axis of rotation of the head restraint to apply the moment required for tilt adjustment. The tilt adjustment moment shall be measured with a suitable transmitter connected to the drive journal at zero lateral force. The head restraint frame shall be adjusted to its middle position (center of adjustment range). The padded head restraint shall be operated through the entire adjusting range from the rearmost to the foremost (lock) position and back. The adjusting moment shall be determined as a function of the adjusting angle: M = f (angle). Adjusting rate is ≤ 20º/s. The adjusting moment shall be determined as the highest moment in the adjusting range within five degrees before the lock position. The result diagram shall be recorded with an XY recorder or a recorder in accordance with the current state of the art. Figure 3: Tilt Adjustment 4.3.1.4 Requirements. The specified values of the height adjustment force and tilt adjustment moment, eventually sleeve releasing knob, are given in the respective part drawing. 4.3.2 Durability Test. Adjust the seat back in design position (if unknown, 25 degrees). A frequency of about six cycles per minute should not be exceeded. The durability test shall be conducted at +23 ± 5ºC. After 8000 full tilt adjustment cycles through the entire tilt adjusting angle, and 1000 cycles through the entire vertical adjustment range, no deformation or wear shall occur which could negatively affect the function. Subsequent to the durability test, vertical GM WORLDWIDE ENGINEERING STANDARDS GMW14604 © Copyright 2007 General Motors Corporation All Rights Reserved February 2007 Page 5 of 8 adjustment force, tilt adjusting moment and sleeve knob releasing force are remeasured (as described in 4.1.2 and 4.1.3) also at +23 ± 5ºC. Adjustment values shall still comply with drawing requirements. Before and after the durability test, the head restraint shall not produce any noise during vehicle operation or on the test stand, and the headset shall lock in any lockable position without slippage. Adjusting noise shall not change due to the durability test. 4.3.3 Integrity Test. This test aims to guarantee the integrity of the headrest and sleeves in case of a force acting in the direction of the head restraint posts, preventing the head rest from detaching of the posts. Three new assembled headrest minimum mounted in a seat back are required. For this test the seat back shall be twisted by 60 mm, measured at a distance of 250 mm from the center of the seatback rotation, and rigidly fixed. The distance between the seatback sides shall be approximately 440 mm (see Figure 4). This requirement shall be fulfilled in any restraint position. A test impact using the head form of 6.8 kg with a velocity of 24.1 km/h shall be performed on the center of the lower side of the head restraint from below, if possible in the direction of the head restraint posts. The head restraint shall not separate from the posts. Inspect the head restraint for loss of pressure, fractures or cracks. Figure 4: Test Setup 4.3.4 Installation and Removal of Head- Restraints. For determination of head restraints removal force inside the vehicle (front seat back and rear back), the head restraint shall be twined around by a strip or a cable. After posts release the head restraint should be removed by a tensile force carried on to the strip or cable. The removal force shall be determined as maximum force over the total length of extension. Avoid canting due to non-uniform removing of the posts. In the normal driving, a head restraint mounted in a bushing shall not cause noises. The specified values are given in the respective part drawing. The head restraint must not be removable without a deliberate action distinct from any act necessary for adjustment. 4.3.5 Adjustment Forces of Head Restraints with Seat Fixed Height Adjustment. The adjustment force shall be initiated in adjustment direction of head restraints posts. Snap rods shall be released before any adjustment. a. Touch key in guide sleeve head restraint. b. For one hand service: Pulling of the head restraint forwards (driving direction). The head restraint shall be moved up and down from upper/lower snapping point to lower/upper snapping point of the snap rods. Avoid canting due to non-uniform pulling or pressing of the snap rods. The adjustment force shall be determined as maximum force over the whole adjusting length. The specified values are given in the respective part drawing. 4.3.6 Foldable Head Restraint Rear Back. 4.3.6.1 Durability Test. The foldable head restraint shall be installed in a rear back or a device which is comparable with a rear back (design position of 25 degrees, if not otherwise noted). After release, the head restraint should be falling down forward. Afterwards the head restraint should be re-moved to starting position. Nine thousand (9000) folds shall be done at +23 ± 5ºC. One thousand (1000) folds shall be done at +80ºC surface temperature of fold mechanism, applied by using a heater lamp (no climatic chamber needed). After 10 000 folds, there should be no detrimental abrasion of function or appearance. If there is no different value dictated on the drawing, the operating force or release force GMW14604 GM WORLDWIDE ENGINEERING STANDARDS © Copyright 2007 General Motors Corporation All Rights Reserved Page 6 of 8 February 2007 respectively should not be exceeded 40 N any time. After each 500 releases, the release force shall be checked. A frequency of about six folds per minute should not be exceeded. 4.3.6.2 Horizontal Free Play Measurement of Foldable Head Restraints. The aim of this test is to measure the free play and the horizontal displacement of head restraints mounted on articulated mechanisms allowing the head restraint to be moved between the usage position (unfolded) and the folded position. A customer complaint because of a loose or weak head restraint shall be avoided. The foldable head restraint shall be mounted in a rear back or in a fixture comparable with a rear back (attached in a design position 25 degrees measured from a vertical reference line, if not otherwise noted). The test shall be performed at +23 ± 5ºC. The test setup is depicted in Figure 5. The point of application for travel and force measuring shall be located 65 mm below the top edge of the head restraint, according to the height measurement procedure to ECE R17. The point of displacement measurement is located at the headrest back side, at the intersection of the headrest contour and the force vector. The displacement shall be measured horizontally. The force vector shall be horizontal and contained in the vertical symmetry plane of the headrest (if not symmetric, calculate the position using the vertical longitudinal plane containing the SgRP). The head restraint shall be loaded with a pre- defined force of 50 N and 200 N respectively, in order to capture free-play and a local weakness resulting from the headrest and the folding system. The force-displacement curve shall be plotted on a diagram. The displacement requirements for each load are (unless otherwise noted in the Subsystem Technical Specification (SSTS). • 10 mm maximum at F 1 = 50 N • 30 mm maximum at F 2 = 200 N Figure 5: Test Set up 4.3.7 Turn Released Head Restraint. 4.3.7.1 Release Force. The release force shall be applied in the upper part of the head restraint. This area is marked in the part drawing. The forces given in the part drawing are applicable. 4.3.7.2 Determination of the Height Adjustment Force for Turn Released Head Restraints. For the determination of the height adjustment force of turn released head restraints, the padded part of the head restraint shall be tilted in driving direction up to release and shall be held in this position. The snap rods shall be clamped. The determination of the height adjustment force shall be done as described in 4.3.1.2. For tiltable head restraints, the tilt shall be turned into front position before the head restraint is released. 4.3.8 Adjustment Forces of Head Restraints with Push Button. The adjustment force shall be initiated in adjustment direction of head restraints posts. Snap rods shall be released before any adjustment with the push button. The head restraint shall be moved up and down from upper/lower snapping point to lower/upper snapping point of the snap rods. Avoid canting due to non-uniform pulling or pressing of the snap rods. The adjustment force shall be determined as maximum force all length of adjusting around. The specified values are given in the relevant part drawing. 4.3.9 Test of Snap Rods for Head Restraints. The snap rods shall be clamped 20 mm below the mounting notch. GM WORLDWIDE ENGINEERING STANDARDS GMW14604 © Copyright 2007 General Motors Corporation All Rights Reserved February 2007 Page 7 of 8 Subsequently a force F shall be applied approximately 15 mm above the upper snap notch (not safety notch). Bend the snap rod for 30 mm minimum without c